1.1

Determine whether the value is from a discrete or continuous data set. Number of bacteria in a petri dish is 12 comma 120Number of bacteria in a petri dish is 12,120 Is the value from a discrete or continuous data​ set?

discrete

determine whether the quantitative variable is discrete or continuous Points scored in an NCAA basketball game

discrete

determine whether the quantitative variable is discrete or continuous. Runs scored in a season by Albert Pujols

discrete

Cluster Sample

divide the population into sections (or clussters), then randomly select some of those clusters, and then choose all members from those selected clusters

A(n) frequency polygon uses line segments to connect points located directly above class midpoint values.

frequency polygon

A parameter

is a numerical summary of a population.

parameter

is a numerical summary of a population.

statistic

is a numerical summary of a sample

individual

is a person or object that is a member of the population being studied.

continuous variable

is a quantitative variable that has an infinite number of possible values that are not countable.

A(n) ____ is a numerical summary of a sample.

statistic

determine whether the underlined value is a parameter or a statistic. Hygiene Habits A study of 6,076 adults in public rest rooms (inAtlanta,Chicago,NewYork City,and San Francisco) found that 23% did not wash their hands before exiting.

statistic

determine whether the underlined value is a parameter or a statistic. Illegal Drugs In a national survey of high school students (grades 9 to 12), 25% of respondents reported that someone had offered, sold, or given them an illegal drug on school property.

statistic

Categorical (or qualitative) Data

Consist of names or labels

Conclusion

Last stage: Do the results have statistical significance ? Do the results have practical significance?

P/S? Employees of a given company

Population

P/S? Number of airplanes owned by an airline.

Population.

Number of unpopped kernals in a bag of microwave popcorn

Quantitative

population

The entire group of individuals to be studied

What's a good idea in terms of size when dealing with these experimental units?

Use the same number of subjects

More convincing data has a ____ z-score

lower

approach

or a way to look at and organize a problem so that it can be solved

The Definition of a​ "Sample" is a​

Subcollection of members selected from a population

Sampling:

A census costs to damn much, so a sample is a count or measure of PART of a population. This is more commonly used in statistical studies.

determine the level of measurement of each variable. Nation of origin

Nominal

Grams of Carbohydrates

Quantitative Data

Variables

Are the characteristics of the individuals within the population. If variables did not vary, they would be constants, and statistical inference would not be necessary.

Determine the level of measurement of the variable below. Volume of water used by a household in a day. Choose the correct answer below.

Ratio

Determine the level of measurement of the variable. Ages of children: 4 years, 5 years, 6 years, 7 years, and 8 years.

Ratio

Complete randomization design

-Subjects are assigned to different Tx groups through random selection. -Experimenter may use blocks. -Commonly used design is a randomized block design.

Determine the level of measurement of the variable. Ages of children: 4 years, 5 years, 6 years, 7 years, and 8 years

Ratio

What does the saying "data vary" mean and how does variability affect the results of statistical analysis?

"Data vary" means that the values of the variable change form individual to individual. In addition, certain variable scan change over time for certain individuals. Because data vary, two different statistical analysis of the same variable can lead to different results. Individuals are different from each other, even if they are similar, you cant be 100% alike someone else, regarding most things in your life.

Is the NUMERICAL value a Para/Stat? The avg annual salary for 35 of a company's 1200 accountants is $68,000.

$68,000 is a numerical description of a sample of annual salaries.

Distinguishing between Discrete and Continuous Variables (c) The distance a 2007 Toyota Prius can travel in city driving conditions with a full tank of gas.

(c) The distance traveled is a continuous variable because we measure the distance.

A news service conducted a survey of 1004 adults ages 18 years or older in a certain​ country, August 31 - September ​2, 2015. The respondents were​ asked, "Of every tax dollar that goes to the federal​ government, how many cents of each dollar would you say are​ wasted?" Of the 1004 individuals​ surveyed, 34​% indicated that 51 cents or more is wasted. The news service reported that 34​% of all adults in the country 18 years or older believe the federal government wastes at least 51 cents of each dollar​ spent, with a margin of error of 3​% and a 90​% level of confidence. Complete parts ​(a) through​ (e) below: (a) What is the research objectives? (b) What is the population? (c) What is the sample? (d) List the descriptive statistics

(a) [[--To determine the percent of adults in the country who believe the federal government wastes 51 cents or more of every dollar]] (b) [[--Adults in the country aged 18 years or older]] (c) [[-- the 1004 adults in the country that were surveyed]] (d) [[-- 34% of the individuals surveyed indicated that 51 cents or more is wasted]] (e) [[-- The news service is 90% confident that the percentage of all adults in the country who believe the federal government wastes 51 cents or more of every dollar received is between 31% and 37%]]

Distinguishing between Qualitative and Quantitative Variables (a) Gender

(a) Gender is a qualitative variable because it allows a researcher to categorize the individual as male or female. Notice that arithmetic operations cannot be performed on these attributes.

Determining the Level of Measurement of a Variable. (a) Gender

(a) Gender is a variable measured at the nominal level because it only allows for categorization of male or female. Plus, it is not possible to rank gender classifications.

Distinguishing between Discrete and Continuous Variables (a) The number of heads obtained after flipping a coin five times.

(a) The number of heads obtained by flipping a coin five times would be a discrete variable because we would count the number of heads obtained. The possible values of the discrete variable are 1,2,3,4...

It is extremely important for a researcher to clearly define the variables in a study because this helps to determine the type of analysis that can be performed ion the data. For example, if a researcher wanted to describe countries based on ISBN (International Standard Book Number) group identifier, what level of measurement would be variable " ISBN group identifier" be? Now suppose the researcher felt that certain countries with greater populations received higher identifying numbers. Does the level of measurement of the variable change? if so, how? (a) What is the level of measurement of the variable "ISBN group identifier" in the original scenario? (b) Does the level of measurement of the variable change in the second scenario?

(a) nominal Because "ISBN group identifiers" is only one number per country, You cant rank each identifier as being better than the other or that there's more of them, because it's just a group identifier, not a group measure. Usually only 1 number per country. (b) Yes, it changes to ordinal Because by assigning higher group identifiers to countries with higher population, you're adding another category of data whose function is to order and organize country according to population. Therefore, categorical with numerical ranking.

Distinguishing between Qualitative and Quantitative Variables (b) Temperature

(b) Temperature is a quantitative variable because it is numeric, and operations such as addition and subtraction provide meaningful results. For example, 70°F is 10°F warmer than 60°F.

Determining the Level of Measurement of a Variable. (b) Temperature

(b) Temperature is a variable measured at the interval level because differences in the value of the variable make sense. For example, 70°F is 10°F warmer than 60°F. Notice that the ratio of temperatures does not represent a meaningful result. For example, 60°F is not twice as warm as 30°F. In addition, 0°F does not represent the absence of heat.

Distinguishing between Discrete and Continuous Variables (b) The number of cars that arrive at a McDonald's drive-through between 12:00 P.M. and 1:00 P.M.

(b) The number of cars that arrive at a McDonald's drive-through between 12:00 P.M. and 1:00 P.M. is a discrete variable because its value would result from counting the cars. The possible values of the discrete variable are 0, 1, 2, 3, 4, and so on. Notice that there is no predetermined upper limit to the number of cars that may arrive.

Distinguishing between Qualitative and Quantitative Variables (c) Number of days during the past week that a college student aged 21 years or older has had at least one drink

(c) Number of days during the past week that a college student aged 21 years or older had at least one drink is a quantitative variable because it is numeric, and operations such as addition and subtraction provide meaningful results.

Determining the Level of Measurement of a Variable. (c) Number of days during the past week that a college student aged 21 years or older has had at least one drink

(c) Number of days during the past week that a college student aged 21 years or older has had at least one drink is measured at the ratio level, because the ratio of two values makes sense and a value of zero has meaning. For example, a student who had four drinks had twice as many drinks as a student who had two drinks.

Determining the Level of Measurement of a Variable. (d) Letter grade earned in your statistics class

(d) Letter grade is a variable measured at the ordinal level because the values of the variable can be ranked, but differences in values have no meaning. For example, an A is better than a B, but A - B has no meaning.

Distinguishing between Qualitative and Quantitative Variables (d) Zip code

(d) Zip code is a qualitative variable because it categorizes a location. Notice that, even though they are numeric, the addition or subtraction of zip codes does not provide meaningful results.

What is a population?

-A collection of ALL outcomes, responses, measurements, or counts that are of interest. -Represents ALL possible measurements or outcomes that are of interest to us in a particular study. -An ENTIRE set of individuals or objects.

Sample

-A subset, or part of a population. -It refers to a portion of the population that is representative of the population from which it was selected.

Finishing times for runners in the Labor Day 10K race.

Ratio

Number of siblings

Ratio

Volume of water used by a household in a day

Ratio

Weights of selected cell phones

Ratio

Preparation Stage

1. Context 2. Sources of the Data 3. Sampling Method

Analysis Stage

1. Graph the data 2. Explore the data 3) Apply statistical methods - Use technology to obtain the results

The Process of Statistics

1. Identify the research objective, 2. Collect the data needed to answer the question(s) posed in (1). 3. Describe the data. 4. Perform inference

The histogram to the right represents the weights​ (in pounds) of members of a certain​ high-school debatedebate team. How many team members are included in the​ histogram? A histogram has a horizontal axis labeled from less than 110 to 170 plus in intervals of 10 and a vertical axis labeled from 0 to 6 in intervals of 1. Vertical bars, 10 units wide and centered on the horizontal axis values, have heights as follows: 110, 4; 120, 0; 130, 0; 140, 3; 150, 1; 160, 0; 170, 5. 110 120 130 140 150 160 170 0 2 4 6

13

A salesperson obtained a systematic sample size of 25 from a list of 500 clients. To do so, he randomly selected a number from 1 to 20, obtaining the number 13. He included in the sample the 13th client on the list and every 20th client thereafter. List the numbers that correspond to the 25 clients selected.

13,33,...,493 Population Size ------------------ = round down to equal k Sample Size Randomly selected number between 1 and k = p p, p + k, p + 2k, p + (n - 1)k

determine the level of measurement of each variable. Assessed value of a house

Ratio

% Data within 1 standard deviation

68%

% Data within 2 standard deviations

95%

% Data within 3 standard deviations

99.7%

What is a Parameter to a Population?

A PARAmeter is a numerical description of a POPulation characteristic

What is a Statistic to a Sample?

A STATistic is a numerical description of a sample

Determine whether the value given below is from a discrete or continuous data set. The volume of cola in a can is 11.5 oz.The volume of cola in a can is 11.5 oz. nothing nothing nothing nothing nothing nothing nothing Choose the correct answer below.

A continuouscontinuous data set because there are infinitely many possible values and thosethere are infinitely many possible values and those values cannot be counted

Determine whether the value given below is from a discrete or continuous data set. The volume of cola in a can is 11.6 oz.The volume of cola in a can is 11.6 oz. nothing nothing nothing nothing nothing nothing nothing Choose the correct answer below.

A continuouscontinuous data set because there are infinitely many possible values and thosethere are infinitely many possible values and those values cannot be counted

Determine whether the value given below is from a discrete or continuous data set. In a test of a method of gender selection comma 690 couples used the XSORT methodIn a test of a method of gender selection, 690 couples used the XSORT method andand 544544 ofof themthem hadhad babybaby girls.girls. Choose the correct answer below.

A discretediscrete data set because there are a finite number of possible valuesthere are a finite number of possible values

Which of the following is associated with a​ parameter?

A parameter is a numerical measurement describing some characteristic of a population.​ So, a parameter is associated with data that were obtained from an entire population.

determine the level of measurement of each variable. Volume of water used by a household in a day

Ratio

Discrete Data

A quantitative variable that has either a finite number of possible values or a countable number of possible values. It can be numerical like numbers of apples but it can be categorical like red or blue. (Data that can take only certain values) Data is COUNTED

Continuous Data

A quantitative variable that is measured and has infinitely many values. Are not restricted to defined separate values, but can occupy any value over a continous range. Data is MEASURED

Define an experimental study:

A researcher deliberately applies a -treatment- before observing responses. -A control group is used where no Tx is applied and are given a placebo. -A treatment group does receive a Tx

Define an observational study:

A researcher doesn't influence the responses. -Observes and measures charac's of interest of part of a population but doesn't change existing conditions.

1. Identify the research objective.

A researcher must determine the question(s) he or she wants answered.The question(s) must be detailed so that it identifies the population that is to be studied.

NOIR LOM? Gender profiles of the 112th Congress: Number - 100, 200, 300, etc Gender - Men, women

Ratio Nominal

What is a voluntary response​ sample?

A sample in which the subjects themselves decide whether to be included in the study. A voluntary response sample is one in which the subjects themselves decide whether to be included in the study.

A scatterplot is a plot of paired data​ (x,y) and is helpful in determining whether there is a relationship between the two variables.

A scatterplot​ (or scatter​ diagram) is a plot of paired​ (x,y) quantitative data with a horizontal​ x-axis and a vertical​ y-axis. The horizontal axis is used for the first​ (x) variable, and the vertical axis is used for the second variable. The pattern of the plotted points is often helpful in determining whether there is a relationship between the two variables.

A histogram aids in analyzing the​ _______ of the data.

A shape of the distribution. A histogram is a visual tool used to represent and analyze data. It is basically a graphic version of a frequency​ distribution, and it can show the​ center, variation, and the shape of the distribution of the data.

Voluntary Response Sample

Respondents decide whether they want to be included

Statisitc

A statistic is a numerical summary of a sample.

What is a​ self-interest study?

A survey in which the sponsor can enjoy monetary or other gains from the results A​ self-interest study is a survey in which the sponsor can enjoy monetary or other gains from the results. Be very wary of studies where the sponsor has certain interests to promote.

Variable

A value or characteristic changes among members of the population.

Interval

A variable is at the interval level of measurement if it has the properties of the ordinal level of measurement and the differences in the values of the variable have meaning. A value of zero in the interval level of measurement does not mean the absence of the quantity. Arithmetic operations such as addition and subtraction can be performed on values of the variable.

Nominal

A variable is at the nominal level of measurement if the values of the variable​ name, label, or categorize. In​ addition, the naming scheme does not allow for the values of the variable to be arranged in a ranked or specific order.

Ordinal

A variable is at the ordinal level of measurement if it has the properties of the nominal level of​ measurement, but the naming scheme allows for the values of the variable to be arranged in a ranked or specific order.

Ratio

A variable is at the ratio level of measurement if it has the properties of the interval level of measurement and the ratios of the values of the variable have meaning. A value of zero in the ratio level of measurement means the absence of the quantity. Arithmetic operations such as multiplication and division can be performed on the values of the variable.

Discrete

A variable that may assume only a countable and usually finite, number of values. A discrete variable is a quantitative variable that has either a finite number of possible values or a countable number of possible values. The term​ "countable" means that the values result from​ counting, such as​ 0, 1,​ 2, 3, and so on.

A(n) _____ is a numerical summary of sample. A(n)_____ is a numerical summary of a population.

A(n) statistic is a numerical summary of sample. A(n) parameter is a numerical summary of a population.

Statistical Significance

Achieved in a study when we get a result that is very unlikely to occur by chance

Voluntary Response Sample

Aka: Self-selected Sample. Is one in which the respondents themselves decide whether to be included (Example: polls like Internet, mail in and phone)

Individual

An individual is a person or object that is a member of the population being studied.

Which branch of statistics, and what conclusions can be drawn from the study using inferential statistics. A study shows that senior citizens who live in Florida have better memories than senior citizens who do NOT live in Florida.

An inference is that senior citizens in Florida have better memories than senior citizens not living in Florida.

What is an observational study? What is a designed experiment? Which allows the researcher to claim causation between an explanatory variable and a response variable? What is an observational study? What is a designed experiment? Which allows the researcher to claim causation between an explanatory variable and a response variable?

An observational study measures the value of the response variable without attempting to influence the value of either the response or explanatory variables. A designed experiment is when a researcher assigns individuals to a certain group, intentionally changing the value of an explanatory variable, and then recording the value of the response variable for each group. A designed experiment

4. Perform inference

Apply the appropriate techniques to extend the results obtained from the sample to the population and report a level of reliability of the results.

Data

Are collections of observations, such as measurements, genders, or survey responses

A​ quality-control manager randomly selects 60 bottles of soda that were filled on June 14 to assess the calibration of the filling machine. What is the population in the​ study?

Bottles of soda produced in the plant on June 14.

A quality-control manager randomly selects 20 bottles of tomato sauce that were filled on March 28 to assess the calibration of the filling machine. What is the population in the study? What is the sample in the study?

Bottles of tomato sauce produced in the plant on March 28. The 20 bottles of tomato sauce produced in the plant on March 28.

Define the descriptive branch of statistics:

Branch of statistics that involves the -->organization, summarization, and --->display<--- of data<--.

Define the inferential branch of statistics:

Branch of statistics that involves using a sample to draw conclusions about a population. A basic tool in the study of inferential statistics is probability.

Interval Level of Measurement

Can be arranged in order, and differences between data value can be found and are meaningful. Data at this level do not have a natural zero starting point at which none of the quantity is present. (example: Temperature, grades)

Ratio Level of Measurement

Can be arranged in order, differences can be found and are meaningful, and there is a natural zero starting point (where zero indicates that none of the quantity is present) (example: Ranks of colleges)

Ordinal Level of Measurement

Can be arranged in some order, but differences (obtained by subtraction) between data values either cannot be determined or are meaningless (example: Course grades)

Nominal Level of Measurement

Characterized by data that consist of names, labels or categories. The data cannot be arranged in an ordering scheme such as low to high (example: Gender)

Systematic Sampling

Chosen by selecting every n-th member of the population (such as every 5th element in the population)

Identify which type of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster. To determine customer opinion of their inflight serviceinflight service​, Continental AirlinesContinental Airlines randomly selects 150150 flightsflights during a certain week and surveys all passengers on the flightspassengers on the flights.

Cluster

Identify which type of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster. To determine customer opinion of their inflight serviceinflight service​, Continental AirlinesContinental Airlines randomly selects 4040 flightsflights during a certain week and surveys all passengers on the flightspassengers on the flights. Which type of sampling is​ used?

Cluster

Identify which type of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster. To determine customer opinion of their pricingpricing​, Home DepotHome Depot randomly selects 7070 check out linescheck out lines during a certain week and surveys all customers in the check out linescustomers in the check out lines. Which type of sampling is​ used?

Cluster

Identify which type of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster. To determine customer opinion of their safety featuressafety features​, Daimler minus ChryslerDaimler−Chrysler randomly selects 7070 service centersservice centers during a certain week and surveys all customers visiting the service centerscustomers visiting the service centers.

Cluster

To determine customer opinion of their safety featuressafety features​, ToyotaToyota randomly selects 150150 dealershipsdealerships during a certain week and surveys all customers visiting the dealershipscustomers visiting the dealerships.

Cluster

To determine the customer opinion of their pricing, Home Depot randomly selects 90 check out lines during a certain week and surveys all customers in the check out lines. What type of sampling is used?

Cluster

A(n) ____ is obtained by dividing the population into groups and selecting all individuals from within a random sample of groups.

Cluster Sample

An educator chooses 5 school districts out of 40 in the Chicago area and asks each household in those districts how mnay school-age children are in the home

Cluster Sample

Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below. A manman experienced a tax audit. The tax department claimed that the manman was audited because everyoneeveryone inin sixsix randomlyrandomly selectedselected districtsdistricts waswas beingbeing audited.audited. nothing nothing nothing Which type of sampling did the tax department​ use?

Cluster Sample

Let's say a population falls into natural occurring subgroups like Zones in a county, zip code, different branches of a bank. What can be used?

Cluster Sample -Each fall into natural occurring subgroups -Divide the groups into clusters, and select all of the members in 1/more (not all) of the clusters.

Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below. A manman experienced a tax audit. The tax department claimed that the manman was audited because everyoneeveryone inin fourfour randomlyrandomly selectedselected districtsdistricts waswas beingbeing audited.audited. nothing nothing nothing Which type of sampling did the tax department​ use?

Cluster Sampling

Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below. A womanwoman experienced a tax audit. The tax department claimed that the womanwoman was audited because everyoneeveryone inin threethree randomlyrandomly selectedselected districtsdistricts waswas beingbeing audited.audited. nothing nothing nothing Which type of sampling did the tax department​ use?

Cluster sampling

Which sampling method divides the population up into​ sections, randomly selects some of those​ sections, then chooses all the members from the selected sections to​ study? Choose the correct answer below.

Cluster sampling involves subdividing the population and using all members from a randomly selected group of subdivisions.

ID the sampling technique: A Pg study in Cebu, Philippines, randomly selects 33 communities from the Cebu metro area, then interviews all Pg women in theses communities.

Cluster sampling is used because each community is considered a cluster and every Pg woman in a selected community is surveyed. A potential source of bias is that selected communities may not be representative of the entire area.

What is the third guideline when designing a statistical study?

Collect the data

Identify which type of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster. Upper A television stationA television station asks its viewersviewers to call in their opinion regarding the variety ofthe variety of sports programming.

Connivence

The definition of​ "Census" is a

Collection of data from every member of a population

What is meant by confounding? What is a lurking variable?

Confounding in a study occurs when the effects of two or more explanatory variables are not separated. Therefore, any relation that may exist between an explanatory variable and the response variable may be due to some other variable or variables not accounted for in the study. A lurking variable is an explanatory variable that was not considered in a study, but is also affected by the casual relationship of the explanatory variables in the study. In addition, lurking variables are typically related to explanatory variables in the study.

Identify which type of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster. Upper A magazineA magazine asks its readersreaders to call in their opinion regarding the quality of thethe quality of the articles.articles. Which type of sampling is​ used?

Connivence

Quantitative (or numerical ) Data

Consist of number representing counts or measurements

Define qualitative data (charac of data):

Consists of attributes, labels, or nonnumerical entries.

Define quantitative data (charac of data):

Consists of numerical measurements or counts.

Determine whether the value is from a discrete or continuous data set. Frequency of a guitar note is 430 HzFrequency of a guitar note is 430 Hz Is the value from a discrete or continuous data​ set?

Continuous

Determine whether the value is from a discrete or continuous data set. Time to learn a song is 4 hoursTime to learn a song is 4 hours Is the value from a discrete or continuous data​ set?

Continuous

Length (in minutes) of a country song

Continuous Data

Time in a race

Continuous Data

What are 3 key elements of a well-designed experiment?

Control Randomization Replication Control those random thoughts of replicating yourself via sexual.

A television station asks its viewers to call in their opinion regarding the variety of sports programming. What type of sampling is used?

Convenience

Identify which type of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster. An internet siteAn internet site asks its membersmembers to call in their opinion regarding their reluctancetheir reluctance to provide credit information online.to provide credit information online. Which type of sampling is​ used?

Convenience

Identify which type of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster. Upper A television stationA television station asks its viewersviewers to call in their opinion regarding the desirabilitythe desirability of programs in high definition TV.of programs in high definition TV. Which type of sampling is​ used?

Convenience

A female student walks down the halls in her dorm asking students how much money they would spend in a food court in the dorm lobby in an effort to pursuade the administration to offer such an option

Convenience Sample

ID the sampling technique: Questioning students as they leave a university library, a researcher asks 358 students about their drinking habits.

Convenience sampling is used because the students are chosen due to their convenience of location. Bias may enter into the sample because the students may not be representative of the population of students.

ID the sampling technique: 25 students are randomly selected from each grade level at a high school and surveyed about their study habits.

Convenience sampling, because all of the people sampled are in one convenient location.

Count or measure of an entire population:

Count that census and spend a census while measuring that population

That Nominal nub needs to qual only!

Data here are qual only. Data at this level is categorized by using names, labels, or qualities. That Nominal nub needs to qual only! Put him in the category that involves calling him names, labeling him a nonqual, and reminding him his quality is NO GOOD. Remember, nominal data simply represents a LABEL.

Define variability and how it affects the analysis of statistics?

Def- difference in the results of different studies even under similar circumstances. Variability affects how reproducible and testable the statistic is. For example, if you go to a dog park on any given day and record different dog sizes, every day could bring different dog breeds, and every day could result in different data. Making your given statistic becomes harder to reproduce. Repeat the experiment at a day care, and the differences in condition wouldn't result in major statistical analysis differences.

What is the fourth guideline when designing a statistical study?

Describe the data, using descriptive statistics techniques.

____ statistics consist of organizing and summarizing information collected, while ____ statistics uses methods that generalize results obtained from a sample to the population and measure the reliability of the results.

Descriptive Inferential

This is an example of what "Suppose 39 of the 50 students stated that they would return the money to theowner.We could present this result by saying the percent of students in the survey that stated they would return the money to the owner is 78%"

Descriptive statistic

Which branch of statistics, and what conclusions can be drawn from the study using inferential statistics. In a sample of Wall Street analysts, the percentage who incorrectly forecasted high-tech warnings in a recent year was 44%.

Descriptive statistics - "The percentage of Wall street analysts who incorrectly forecasted high-tech earnings in a recent year was 44%." A possible inference drawn from the study is that the stock market is difficult to forecast, even for professionals.

Which branch of statistics, and what conclusions can be drawn from the study using inferential statistics. A large sample of men, 48, was studied for 18 years. For unmarried men, 70% were alive at age 65. For married men, 90% were alive at age 65.

Descriptive statistics - For unmarried men, 70% were alive at age 65," and "for married men, 90% were alive at age 65. A possible inference includes that being married is associated with a longer life for men.

Descriptive

Descriptive statistics consists of organizing and summarizing information collected.

What is the second guideline when designing a statistical study?

Develop a detailed plan for collecting the data. If you use a sample, make sure the sample is representative of the population.

Determine whether the value is from a discrete or continuous data set. Number of members present at a meeting is 6Number of members present at a meeting is 6 Is the value from a discrete or continuous data​ set?

Discrete

Determine whether the value is from a discrete or continuous data set. Number of pieces of lumber used to make a deck is 113Number of pieces of lumber used to make a deck is 113

Discrete

Number of students in a class

Discrete Data

Points scored in an NCAA basketball game

Discrete Data

Determine whether the value given below is from a discrete or continuous data set. In a test of a method of gender selection comma 730 couples used the XSORT methodIn a test of a method of gender selection, 730 couples used the XSORT method andand 407407 ofof themthem hadhad babybaby girls.girls. Choose the correct answer below.

DiscreteA discretediscrete data set because there are a finite number of possible valuesthere are a finite number of possible values nothing Your answer is correct.B.

Systematic Sample:

Each member of a population is assigned a number, ordered in a particular way, and picked at regular intervals from the starting number.

ID the sampling technique: Opinion of students on stem cell research. You assign each student a number and generate random numbers. You then question each student whose number is randomly selected.

Each sample of the same size has an equal chance of being selected and each student has an equal chance of being selected, so this is a simple random sample.

A student entering a doctoral program in educational psychology is required to select three courses from the list of courses provided as part of his or her program. List all possible three-course selections. Comment on the likelihood that EPR 651, EPR 602, and EPR 631 will be selected.

Ensure no repeating answers in selection There is a 1 in 10 likelihood.

What does it mean if a statistic is resistant?

Extreme values (very large or small) relative to the data do not affect its value substantially.

Determine whether the description corresponds to an observational study or an experiment. Thirty university students are divided into two groups. One group receives freeThirty university students are divided into two groups. One group receives free tutoring in mathematics comma the other doesn't.tutoring in mathematics, the other doesn't. After one semester comma scores on finalAfter one semester, scores on final mathematical examinations are compared.mathematical examinations are compared. Does the description correspond to an observational study or an​ experiment?

Experiment

Sixty patient with carpal tunnel syndrome are randomly divided into two groups. One group is treated weekly with both acupuncture and an exercise regimen. The other is treated weekly with the exact same exercise regimen, but no acupuncture. After one year, both groups are questioned about their level of pain due to CTS.

Experiment

Seventh grade students are randomly divided into two groups. One group in taught math using traditional techniques: the other is taught math using a reform method. After one year, each group is given an achievement test to compare proficiency.

Experimental

What is a confounding variable?

Experimental results can be ruined by a variety of factors. One is a confounding variable. The experimenter is so confounded because he can't tell the difference between the effects of different factors on the variable.

T/F: In​ statistics, results are always reported with​ 100% certainty.

False. In​ statistics, results are not reported with​ 100% certainty. Because statistical studies draw on​ samples, and because there is variation within​ groups, results cannot be reported with​ 100% certainty.

T/F: Statistical studies are not concerned with understanding the sources of variability in​ data, only with describing the variability in the data. Choose the correct answer below.

False. Statistical studies are concerned with both describing the variability in the data and understanding the sources of variability in data. Understanding the sources allows researchers to control it and reach better conclusions.

Think about the table with the Yankees' World series victories (yrs). What data level does this constitute?

First, the years represent quant data. You can find differences (subtraction) between specific dates like finding out how many years it's been since they won. It doesn't make any sense to say one year is a multiple of another making this data at the interval level.

the Heights of the bars of a histogram correspond to ____ values.

Frequency. A histogram is a graph consisting of bars of equal width drawn adjacent to each other​ (without gaps). The horizontal scale represents classes of quantitative data values and the vertical scale represents frequencies. The heights of the bars correspond to the frequency values.

2. Collect the data needed to answer the question(s)

Gaining access to an entire population is often difficult and expensive. When conducting research, we typically look at a sample. The collection of data step is vital to the statistical process, because if the data are not collected correctly, the conclusions drawn are meaningless. Do not overlook the importance of appropriate data-collection processes.

Which of the following would be classified as categorical​ data?

Hair color would be classified as categorical data. Categorical data consist of names or labels that are not numbers representing counts or measurements.

What is the Hawthorne Effect?

Hawthorne was a FILZY JEW who realized subjects would change their shape/behavior simply because they knew they were participating in an experiment.

Think about the table about the 2012 American League home run totals (by team).

Here you CAN find differences AND write ratios. From the data, you can see that Bmore hit 39 more home runs as Detroit hit. This data is at the ratio level.

A published study looked at levels of a protein released when the heart is stressed. Researchers measured the protein levels in 1031 patients and followed their health for seven years. People with the highest protein level were 1 1/2 times more likely to die from any cause than those with the lowest. The lead researcher said, "It sort of tells you that no matter what conditions you have, higher levels of these proteins are associated with worse outcomes." Identify the research question the study addresses Identify the population. Identify the sample. Identify the descriptive statistics. Identify the inferences of the study.

How is the level of a certain protein associated with a person's health? All people. The 1031 patients in the study. People with the highest levels of the protein were 1.5 times more likely to die than those with the lowest values. Higher levels of the protein are associated with worse outcomes.

What is the sixth guideline when designing a statistical study?

Identify any possible errors

What is the first guideline when designing a statistical study?

Identify the variable(s) of interest (the focus) and the population of the study.

A bar chart and a Pareto chart both use bars to show frequencies of categories of categorical data. What characteristic distinguishes a Pareto chart from a bar​ chart, and how does that characteristic help us in understanding the​ data?

In a Pareto​ chart, the bars are always arranged in descending order according to frequencies. The Pareto chart helps us understand data by drawing attention to the more important​ categories, which have the highest frequencies. A bar chart uses bars of equal width to show frequencies of categorical data. The vertical scale represents frequencies or relative frequencies. The horizontal scale identifies the different categories of qualitative data. When one wants a bar chart to draw attention to the more important​ categories, one can use a Pareto​ chart, which is a bar chart for categorical​ data, with the added stipulation that the bars are arranged in descending order according to frequencies. The bars decrease in height from left to right.

Identify which type of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster. To determine customer opinion of their pricingpricing​, AmtrakAmtrak randomly selects 4040 trainstrains during a certain week and surveys all passengers on the trainspassengers on the trains. Which type of sampling is​ used?

In a random sample members from the population are selected in such a way that each individual member has an equal chance of being selected. In systematic sampling​, select some starting point and then select every kth element in the population. With convenience sampling​, simply use results that are very easy to get. With stratified sampling​, subdivide the population into at least two different subgroups​ (or strata) so that subjects within the same subgroup share the same​ characterisitcs, then draw a sample from each subgroup​ (or stratum). In cluster sampling​, first divide the population area into sections​ (or clusters), then randomly select some of the​ clusters, and then choose all the members from those selected clusters. Cluster

A(n) ____ is a person or object that is a member of the population being studied.

Individual

If we extend the results of our sample to the population and say that the proportion of all students at the school who would return the money is 78%, we are performing

Inferential statistics

Inferential

Inferential statistics uses methods that generalize results obtained from a sample to the population and measure the reliability of the results.

What is the fifth guideline when designing a statistical study?

Interpret the data and make decisions about the population using inferential statistics.

A discretediscrete data set because there are a finite number of possible valuesthere are a finite number of possible values

Interval

Boiling points (on the Celsius scale) for various caramel candies

Interval

Determine the level of measurement of the variable below. Time of day measured in military time. Choose the correct answer below.

Interval

Determine the level of measurement of the variable. Monthly temperatures: 61 degrees F, 65 degrees F, 69 degrees F, 73 degrees F, and 77 degrees F Choose the correct answer below.

Interval

Determine the level of measurement of the variable. Years of elections: 1988, 1992, 1996, 2000, and 2004

Interval

Temperatures inside 10 pizza ovens

Interval

NOIR LOM? Items on a Physicians intake form Find the LOM. Temp, Allergies, Weight, Pain level.

Interval Nominal Ratio Ordinal

Low temperatures in degrees Fahrenheit across the state for one evening in march

Interval (differences is meaningful)

LOM NOIR - The years of birth for the runners in the Boston marathon

Interval - because meaningful differences between entries can be calculated, but a zero entry is not an inherent zero.

What's the significant difference between Ordinal and Interval LOM?

Interval data can also be ordered, and meaningful differences between data entries CAN BE calculated. Here, a zero entry simply represents a position on a scale; the entry itself is NOT an inherent/essential zero. Like having zero dollars in your bank account. It means nothing and represents NO MONEY. A temp of 0 degrees C doesn't represent something where not heat is present. It's simply a position on the Celsius scale - it is NOT an inherent zero.

Avg monthly Temps (F) for Denver, Co. - NOIR LOM? Jan 30.7 Feb 32.5 ...

Interval where it's qual and quant, put in order, and you CAN FIND DIFFERENCES BETWEEN VALUES.

NOIR LOM? Years a TV show on ABC won the Emmy for best comedy series: 1955, 1981, 2912

Interval. Data can be ordered, meaningful differences can be calculated, but it doesn't make sense to say one year is a multiple of another.

Statistic

Is a numerical summary of a sample, which is a subset of the population that is being studied. Statistics is the science of​ collecting, organizing,​ summarizing, and analyzing information to draw a conclusion and answer questions. In​ addition, statistics is about providing a measure of confidence in any conclusions.

Parameter

Is a numerical summary of population, which is an entire group to be studied.

Sample

Is a subcollection of members selected from a population

Census

Is the collection of data from every member of the population

Population

Is the complete collection of all measurements or data that are being considered

Statistics

Is the science of planning studies and experiments; obtaining data; and then organizing, summarizing, presenting, analyzing and interpreting those data and then drawing conclusions based on them

Determine whether the sampling method described below appears to be sound or is flawed. In a survey of 529human resource​ professionals, each was asked about the importance of the appearance of a job applicant. The survey subjects were randomly selected by pollsters from a reputable market research firm.

It appears to be sound because the data are not biased in any way.

Determine whether the sampling method described below appears to be sound or is flawed. In a survey of 674subjects, each was asked how often he or she read a book. The survey subjects were internet users who responded to a question that was posted on a news website.

It is flawed because it is a voluntary response sample.

Determine whether the given value is from a discrete or continuous data set. When a busbus is randomly​ selected, it is found to have a tire pressure of 32 psia tire pressure of 32 psi. Choose the correct answer below.

It is from a continuouscontinuous data set because the number of possible values is infiniteinfinite andand not countablenot countable.

Determine whether the given value is from a discrete or continuous data set. When a trucktruck is randomly​ selected, it is found to have a gas tank that can hold 18 gala gas tank that can hold 18 gal. Choose the correct answer below.

It is from a continuouscontinuous data set because the number of possible values is infiniteinfinite andand not countablenot countable.

Determine whether the given value is from a discrete or continuous data set. When a trucktruck is randomly​ selected, it is found to have a gas tank that can hold 19.4 gala gas tank that can hold 19.4 gal.

It is from a continuouscontinuous data set because the number of possible values is infiniteinfinite andand not countablenot countable.

Determine whether the given value is from a discrete or continuous data set. When a busbus is randomly​ selected, it is found to have 2 wipers2 wipers. Choose the correct answer below.

It is from a discretediscrete data set because the number of possible values is finitefinite oror countablecountable.

Inferences based on voluntary response samples are generally not reliable because

It is often the case that individuals who volunteer do not accurately represent the population. e.g. because the certain volunteers who respond, might have very strong feelings either way, or not truly belong in the studied population. All of which introduces bias.

Whats a cross sectional study?

It's an observational study that collects info at a specific point in time or over a short period. an advantage of cross-sectional studies is that they are cheap and quick to do, however limited on long term results, on weather or not something changed after the initial cross-sectional study was performed.

convenience samples

Many nonscientific studies are based on Internet surveys or phone-in polls. The results of any study performed using this type of sampling method are not reliable.

Experimental design where subjects are paired up according to a similarity be it age, geographical location, or physical charac.

Matched-pairs design. One receives Tx/ one placebo or different Tx.

Simple Random Sampling

Mean that every sample from the population has an equal chance of being chosen

Data consists of MOC information observed by Count Chocula where does it come from?

Measurements or responses Observations Counts

youryour oddsodds ofof carcar thefttheft byby nbsp 300 percent." 300 percent." What is wrong with this​ statement?

Misleading

Analyzing Data - Potential Pitfalls

Misleading conclusions Small samples Question wording Order of questions Nonresponse Missing Data

Based on a study of agesages of men and women whowho have childrenhave children​, a researcher concludes that being a parentbeing a parent causes people to ageage. Do you agree with this​ conclusion?

No. There may be a relationship between having childrenhaving children and the age of an adultthe age of an adult​, but that does not mean that one causes the other.

Categories of magazines in a physician's office (sports, women's health, men's news)

Nominal

Colors contained in a box of crayons

Nominal

Determine the level of measurement of the variable below. Eye color Choose the correct answer below.

Nominal

Determine the level of measurement of the variable. Dress color

Nominal

Determine the level of measurement of the variable. Nation of origin

Nominal

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Favorite colorsFavorite colors Choose the correct level of measurement.

Nominal

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Hair colorsHair colors Choose the correct level of measurement.

Nominal

Martial Status

Nominal

Nation of Origin

Nominal

The genre of the music performed at the 2013 Grammy's

Nominal

Types of pets reported in a recent survey

Nominal

It is extremely important for a researcher to clearly define the variables in a study because this helps to determine the type of analysis that can be performed on the data. For example, if a researcher wanted to describe cities based on zip code, what level of measurement would the variable "zip code" be? Now suppose the researcher felt that certain cities with a higher population density received higher zip codes. Does the level of measurement of the variable change? If so, how? What is the level of measurement of the variable "zip code" in the original scenario? Does the level of measurement of the variable change in the second scenario?

Nominal Yes, it changes to ordinal

Another charac of data includes a form of measurement while drinking NOIR

Nominal Ordinal Interval Ratio

Jersey Numbers of players on a Lacrosse team

Nominal (jersey number is a category)

TV Shows - NOIR LOM? Comedy, Drama, etc

Nominal with a meaningful calculation - a show televised by the network could be put into 1/8 categories shown.

NOIR LOM? Jersey numbers for players on a soccer team: 5, 9, 88, 8, etc...

Nominal. No mathematical computations can occur and data is organize using numbers.

Distinguish between nonsampling error and sampling error.

Nonsampling error is the error that results from the process of obtaining the data. Sampling error is the error that results because a sample is being used to estimate information about a population.

A(n) _______ distribution has a​ "bell" shape.

Normal. When​ graphed, a normal distribution has a​ "bell" shape. Characteristics of the bell shape are​ (1) the frequencies increase to a​ maximum, and then​ decrease, and​ (2) symmetry, with the left half of the graph roughly a mirror image of the right half. Next Question

Parameter

Numerical measurement describing some characteristic of a population. Tells us something about the whole population

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Positions of runners in a racePositions of runners in a race Choose the correct level of measurement.

ORDINAL

A survey is conducted asking 400 people "Do you prefer coke or pepsi?"

Observational

Research wanted to know if there is a link between proximity to high-tension wires and the rate of leukemia in children. To conduct the study, researches compared the incidence rate of leukemia for children who lived within 1/3 mile of high-tension wires to the incidence rate of leukemia for children who did not live within 1/3 mile of high-tension wires

Observational Studies

A study is conducted to measure​ children's growth rates without any treatment applied to the children. What best classifies this​ study? Choose the correct answer below.

Observational study involves observing and measuring specific characteristics without attempting to modify the subjects being studied.

What is an observational study, and can it determine causation?

Observing and recording data without influence. measures the response variable without trying to influence and control either the response, or explanatory variable. *Cannot claim causation between an explanatory variable and a response variable because it could not influence or control either one to determine which caused what.

3. Describe the data

Obtaining descriptive statistics allows the researcher to obtain an overview of the data and can provide insight as to the type of statistical methods the researcher should use

What does it mean when sampling is done without replacement?

Once an individual is selected, the individual cannot be selected again.

What is a biased sample?

One that is not representative of the population from which it's drawn. A sample consisting of only 18-22 y/o students would not represent ALL of the 18-22 population in the country.

Determine the level of measurement of the variable. Positions of persons in a line

Ordinal

Determine the level of measurement of the variable. Ranks of scores in a tournament. Choose the correct level of measurement.

Ordinal

Determine the level of measurement of the variable. Finishing ranks of swimmers in a swim meet

Ordinal

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. The rankings of songs in the top 100The rankings of songs in the top 100 Choose the correct level of measurement.

Ordinal

Highest degree conferred (high school, bachelor and etc)

Ordinal

Ranking of golfers in a tournament

Ordinal

Ratings of textbooks (poor, fair, good, excellent)

Ordinal

The seat numbers on your concert tickets, such as A23 and A24

Ordinal

The top ten Spring Break destination as ranked by MTV

Ordinal (its just ranking)

Position in line at the checkout counter of a grocery store

Ordinal (ranking by position in line)

LOM NOIR - List of badge numbers of police officers at a precinct.

Ordinal - badge numbers can be ordered and often indicate seniority of service, but no meaningful math can be performed.

LOM NOIR - The top 10 grossing films released in a year

Ordinal - because data can be arranged in order, but the differences between data entries make no sense.

Ordinary ordinal measurements are qual or quan data. Define.

Ordinal data measurements are not ordinary, they are qual or quan arranged in order, ranked, but differences between data entries are NOT MEANINGUL. Ordinary military people are normally placed in order and ranked, but differences between them and their data entries (where they're from) are NOT meaningful.

Motion picture association of America ratings - NOIR LOM? G, PG, etc.

Ordinal where it's qual and quant. A PG rating has a stronger restriction than a G rating.

NOIR LOM? Top 5 fiction books on the NYT best sellers list on 12/23/12: 1. Threat Vector 2. Gone Girl 3. The Forgotten

Ordinal. Data can be arranged in order, but differences between data entries are not meaningful.

State Government: Following the 2006 national midterm election, 18% of all governors of the 50 US were female.

Parameter

Determine where the given value is a statistic or parameter. In a study of all 2771 seniors at a college, it is found that 25% own a vehicle.

Parameter because the value is a numerical measurement describing a characteristic of a population.

Determine whether the given value is a statistic or a parameter. In a study of all 1294 students at a college comma it is found that 45 % own a television.In a study of all 1294 students at a college, it is found that 45% own a television. Choose the correct statement below.

Parameter because the value is a numerical measurement describing a characteristic of a populationpopulation.

Determine whether the given value is a statistic or a parameter. In a study of all 3336 seniors at a college comma it is found that 55 % own a vehicle.In a study of all 3336 seniors at a college, it is found that 55% own a vehicle. Choose the correct statement below.

Parameter because the value is a numerical measurement describing a characteristic of a populationpopulation.

Determine whether the underlined numerical value is a parameter or a statistic. Explain your reasoning. For a certain movie, 64.3 % of the 112 members of the audience were females.

Parameter, because the data set of all 112 audience members is a population

Determine whether the underlined numerical value is a parameter or a statistic. Explain your reasoning. In a certain soccer league, 43 % of the 14 teams had won more games than they had lost.

Parameter, because the data set of all 14 teams is a population

Determine whether the underlined numerical value is a parameter or a statistic. *Two* students in a class of 29 have red hair.

Parameter, because the data set of all 29 students is a population.

Is the NUMERICAL value a Para/Stat? In a recent study of math majors at a university, 10 students were minoring in physics.

Parameter. The 10 students minoring in physics is a numerical description of all math majors at a university.

Is the NUMERICAL value a Para/Stat? 62 of the 97 passengers aboard the Hindenburg airship survived its explosion.

Parameter. The 62 surviving passengers out of 97 total passengers is a numerical description of all of the passengers of the Hindenburg that survived.

Is the NUMERICAL value a Para/Stat? At a college, 90% of the members of the Board of Trustees approved the contract of the new president.

Parameter. The 90% of members that approved the contract of the new president is a numerical description of all board of Trustees members.

Is the NUMERICAL value a Para/Stat? In 2012, MJB teams spent a total of over 2 millions on player's salaries.

Parameter. The value over 2 million is a numerical description of the total player salary for all of the players in MLB.

Determine whether the given value is a statistic or a parameter. In a study of all 1452 students at a college comma it is found that 45 % own a computer.In a study of all 1452 students at a college, it is found that 45% own a computer. Choose the correct statement below.

ParameterParameter because the value is a numerical measurement describing a characteristic of a populationpopulation.

Determine whether the given value is a statistic or a parameter. In a study of all 4171 professors at a college comma it is found that 45 % own a television.

ParameterParameter because the value is a numerical measurement describing a characteristic of a populationpopulation.

Qualitative

Pertaining to or concerned with quality or qualities. Qualitative variables allow for classification of individuals based on some attribute or characteristic.

P/S? The grains of sand on the beaches of the world.

Population

P/S? The number of widgets manufactured by a company that plans to be in business forever.

Population

2 Types of data sets used when studying statistics

Population Sample

Is the NUMERICAL value a Para/Stat? The freshman class at a university has an average SAT math score of 514

Population Parameter

P/S? The political party of every president.

Population because it is a collection of ALL the US presidents' political parties.

P/S? Potential consumers in a target market.

Population.

P/S? Final score of each golfer in a tournament.

Population. Because it is a collection of ALL the golfers' scores in the tournament.

P/S? Revenue of each of the 30 companies in the Dow Jones Industrial Average.

Population. It's a collection of the revenues of the 30 companies in the DJIA. It represents ALL possible measurements or outcomes interested in this particular study.

Which is the population and sample? A. Ages of adults in the US who own cell phones B. Ages of adults in the U.S. who own Samsung cell phones

Population: A Sample: B

Which is the population and sample? A. Parties of registered voters in Warren County? B. Parties of Warren County voters who respond to online survey.

Population: A Sample: B

Find the population and sample: Survey of 55 US law firms found the average hourly billing rate was $425.

Population: Collection of the average hourly billing rates of all US law firms Sample: Collection of the average hourly billing rates of the 55 US law firms surveyed.

Find the population and sample: Survey of 202 pilots found that 20% admit that they have made a serious error due to sleepiness.

Population: Collection of the effect of sleepiness on all pilots Sample: Collection of the effect of sleepiness on the 202 pilots surveyed.

Find the population and sample: Survey of 12,082 US adults found that 45.5% received the flu vaccine for a recent flu season.

Population: Collection of the immunization status of all adults in the US. Sample: Collection of the immunization status of the 12,082 US adults surveyed.

ID the population and sample: A Study of dietary habits of 20,000 men was conducted to find a link between high intakes of dairy products and prostate cancer.

Population: Collection of the prostate conditions of all men Sample: Collection of the prostate conditions of the 20,000 men in study.

Find the population and sample: Survey of 2311 US adults found that 84 % have seen a health care provider at least once in the past year.

Population: Collection of the responses of all US adults Sample: Collection of the responses of the 2311 US adults that were sampled

Find the population and sample: Survey of 1503 US adults found that 78% favor government policies requiring better fuel efficiency for vehicles.

Population: Collection of the responses of all US adults Sample: Collection of the responses of the 1503 US adults that were sampled

Find the population and sample: A survey of 1015 US adults found that 32% have had to put off medical care for themselves or their family in the part year due to the cost.

Population: Collection of the responses of all adults in the US Sample: Collection of the responses of the of the 1015 US adults surveyed

Find the population and sample: To gather information about starting salaries at companies listed in the Standard & Poor's 500, a researcher contacts 65 of the 500 companies.

Population: Collection of the starting salaries at all 500 companies listed in the Standard & Poor's 500. Sample: Collection of the starting salaries of the 65 companies listed in the Standard & Poor's 500 that were contacted by the researcher.

Random Sampling

Process of using chance to select individuals from a population to be included in the sample

Ordinal LOM charac:

Qual or Qual where you can: -Put data in categories -Arrange data in order

Interval LOM charac:

Qual or Qual where you can: -Put data in categories -Arrange data in order -Subtract data values

Ratio LOM charac:

Qual or Qual where you can: -Put data in categories -Arrange data in order -Subtract data values -Determine whether one data value is a multiple of another

Nominal LOM characteristic:

Qual where you can: -Put data in categories

Determine whether the following information is qualitative or quantitative: List of debit car pin numbers

Qual, because debit pin numbers are labels and it does not make sense to find differences between numbers

Determine whether the following information is qualitative or quantitative: Eye colors of models

Qual, because eye colors are attributes

Determine whether the following information is qualitative or quantitative: Responses on an opinion poll

Qual, because the poll responses are attributes

Determine between qual/quant, and LOM of the data: Top Salespeople. The regions representing the top salespeople in a corporation for the past six years. Southeast Northwest Northeast Southwest

Qual. Nominal. No math can occur and data are categorized by region.

Determine between qual/quant, and LOM of the data: Top 5 music albums for 2012. 1. Adele - 21 2. Michael Buble - Xmas 3. Drake - Take Care 4. Taylor Swift - Red

Qual. Ordinal. Data can be arranged in order but the differences between data entries make no sense.

Nation of Origin

Qualitative Data

Determine between qual/quant, and LOM of the data: Football. Top 5 teams in the final college football poll released in Jan 2013. 1. Alabama 2. Oregon 3. Ohio State

Qualitative. Ordinal. Data can be arranged in order, but the differences between data entries are NOT meaningful.

Determine whether the following information is qualitative or quantitative: The ages of a sample of 350 employees of a software company.

Quant, because ages are numerical measurements

Determine whether the following information is qualitative or quantitative: Heights of hot air balloons

Quant, because balloon heights are numerical measurements

Determine whether the following information is qualitative or quantitative: The final scores of a video game

Quant, because final scores are numerical measurements

Determine whether the following information is qualitative or quantitative: Weights of infants at a hospital

Quant, because infant weights are numerical measurements

Determine whether the following information is qualitative or quantitative: The revenues of the companies on the Fortune 500 list.

Quant, because revenues are numerical measurements

Which of the following is NOT a level of​ measurement?

Quantitative refers to a data​ type, not a level of measurement.

Choose the correct answer below

Quiz scores from a college level statistics course are analyzed to determine student progress. Using quiz scores from a college level statistics course that are analyzed to determine student progress would not be a voluntary response sample because respondents themselves do not decide to be included.

Determine who will win a $100,000 shopping spree at the mall.The manager draws the name out of a box of entries

Random Sampling (because every name in the box has an equal chance of being chosen)

Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below. A manman experienced a tax audit. The tax department claimed that the manman was audited because hehe waswas randomlyrandomly selectedselected fromfrom allall thethe taxpayers.taxpayers. nothing nothing nothing nothing Which type of sampling did the tax department​ use?

Random sampling

Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below. In a poll conducted by a certain research​ center, 12091209 adults were called after their telephone numbers were randomly generated by a​ computer, and 3 %3% were able to correctly identify the secretary of state.secretary of state. Which type of sampling did the research center​ use?

Random sampling

Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below. In a poll conducted by a certain research​ center, 793793 adults were called after their telephone numbers were randomly generated by a​ computer, and 83 %83% were able to correctly identify the president.president. Which type of sampling did the research center​ use?

Random sampling

Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below. In a poll conducted by a certain research​ center, 894894 adults were called after their telephone numbers were randomly generated by a​ computer, and 9 %9% were able to correctly identify the secretary of state.secretary of state. Which type of sampling did the research center​ use?

Random sampling

Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below. In a poll conducted by a certain research​ center, 900900 adults were called after their telephone numbers were randomly generated by a​ computer, and 20 %20% were able to correctly identify the president.president. Which type of sampling did the research center​ use?

Random sampling

Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below. In a poll conducted by a certain research​ center, 911911 adults were called after their telephone numbers were randomly generated by a​ computer, and 55 %55% were able to correctly identify the president.president. Which type of sampling did the research center​ use?

Random sampling

A process of randomly assigning subjects to different treatment groups:

Randomization

Ages of Children in Daycare Center

Ratio

NOIR LOM? How serious of a Problem is Global Warming? Percents - 5, 10, 15, etc Reponse- Very serious, Somewhat serious, not too serious, etc...

Ratio Ordinal

LOM NOIR - Horsepower of racing car engines

Ratio - because on data entry can be expressed as a multiple of another.

Avg monthly precipitation (in) in Orlando, Fl - NOIR LOM? Jan 2.35 Feb 2.38 ...

Ratio where it's both qual and quant, put in order, you can find differences between values, AND find RATIOS OF VALUES: 7.58/3.77 = 2 Here, there's TWICE AS MUCH rain in June as March

A​ _______ histogram has the same shape and horizontal scale as a​ histogram, but the vertical scale is marked with relative frequencies instead of actual frequencies.

Relative frequency. A histogram is a graph consisting of bars of equal width drawn adjacent to each other​ (without gaps). A relative frequency histogram has the same shape and horizontal scale as a​ histogram, but the vertical scale is marked with relative frequencies​ (as percentages or​ proportions) instead of actual frequencies. Next Question

Replication improves the validity of the experimental results, what is it?

Repetition of an experiment under the same or similar conditions.

What's a designed experiment and can it determine causation?

Researcher assigns the individuals in a study to a certain group, and intentionally changes the vale of an explanatory variable, and then records the value of the response variable in each group. *Can determine causation between an explanatory variable and a response variable

Determine whether the results below appear to have statistical​ significance, and also determine whether the results have practical significance. In a study of a weight loss​ program, 4 subjects lost an average of 44 lbs. It is found that there is about a 21​% chance of getting such results with a diet that has no effect. Does the weight loss program have statistical​ significance? Does the weight loss program have practical​ significance?

Results are said to be statistically significant if they are unlikely to occur solely by chance. No, the program is not statistically significant because the results are likely to occur by chance. The statistical significance of a study can differ from its practical significance. It is possible​ that, based on the available sample​ data, statistical methods can be used to reach a conclusion that a weight loss program is​ effective, but common sense might suggest that the program does not make enough of a difference to justify its use or to be practical. Yes, the program is practically significant because the amount of lost weight is large enough to be considered practically significant.

ID the sampling technique: Chosen at random, 580 customers at a car dealership are contacted and asked their opinions of the service they received.

SRS. Because each customer has an equal chance of being contacted, and all samples of 580 customers have an equal chance of being selected.

Is the NUMERICAL VALUE a Para/Stat? Recent survey of approximately 400,000 employers reported that the average salary for marketing majors is $53,4000

Sample Statistic

Is the NUMERICAL value a Para/Stat? In a random check of 400 retail stores, the FDA found the 34% of the stores were not storing fish at the proper temperature.

Sample Statistic

Convenience Sampling

Sample in which the individuals are easily obtained and not based on randomness

ID the sampling technique: Opinion of students on stem cell research. You select students who are in your biology class.

Sample is taken from something readily available - convenience sample. Sample may be biased because biology students can be more familiar with stem cell research than others.

Convenience sample

Sample often leading to bias and not recommended. It consists only of members easy to get.

The number of subjects in a study

Sample size, also known as n

Simple random sample:

Sample where every possible -sample- of the sample size has the same chance of being selected. A member of the sample chosen.

P/S? Cholesterol levels of 20 patients in a hospital with 100 patients.

Sample. Because the collection of the 20 patients is a SUBSET of the population of 100 patients at the hospital.

P/S? Survey of 500 spectators from a stadium with 42,000 spectators.

Sample. The collection of the 500 spectators is a subset of the population of 42,000 spectators at the stadium.

If it's acceptable to have a member of a same population is selected more than once:

Sampling process is said to be -with replacement-

Explain what is meant when it is said that​ "data vary". How does the variability affect the results of statistical​ analysis?

Saying​ "data vary" means that the values of the variable change from individual to individual. In​ addition, certain variables can change over time for certain individuals. Because data​ vary, two different statistical analysis of the same variable can lead to different results. Similar individuals will not necessarily yield the same data. People can be different​ heights, different​ weights, different​ ages, and so on. In addition to​ this, a​ person's age will change over​ time, and their height and weight can change over time as well. Measuring two​ people's heights at the same​ time, or measuring one​ person's height at different times can yield different results.

Systematic Sample

Select every Kth individual from a population, starting with the first 3rd individual etc. between on and K. Like randomly selecting every forth customer at a grocery line to take a serving starting after the first 5th, random selection with a structured format.

Ratio LOM.

Similar to Interval and here that little zero IS a hero! Here, a ratio of two data entries can be formed so that one data entry can be meaningfully expressed as a multiple of another. Think about the twice as much concept. 2 buck is twice as much as 1 buck. 2 degrees C is NOT twice as warm as 1 degree C (This data would be at the interval level).

For wants to administer a satisfaction survey to its current customers. Using their customer database, the company randomly selects 90 customers and asks them about their level of satisfaction with the company. What type of sampling is used?

Simple random

ID the sampling technique: Using random digit dialing, researchers call 140 people and ask what obstacles (childcare) keep them from exercising.

Simple random sampling because each telephone umber has an equal chance of being dialed, and all samples of 1400 phone numbers have an equal chance of being selected. The sample may be biased because telephone sampling only samples those individuals who have telephones, who are available and who are willing to respond.

ID the sampling technique: Using random digit dialing, researchers ask 1003 US adults their plans on working during retirement.

Simple random sampling is used because random telephone numbers were generated and called. A potential source of bias is that telephone sampling only samples individuals who have telephones, available, and willing to participate.

There are several ways of collecting data - S/S This one gets all 'Mathy' on you, reminds you just bought a LEGIT Lenovo laptop, and you don't even have to worry about life/death situations while saving time and money.

Simulation: -Use of a mathematical or physical model to reproduce the conditions of a situation or process. -Data collection often uses computers -Allows you to study situations impractical or even dangerous to create in real life, often saving time and money.

Datum

Single data value

Hygiene Habits: A study of 6076 adults in public rest rooms (in Atlanta, Chicago, NYC and SF) found that 23% did not wash their hands before exiting

Statistic

In a national survey high school students grades 9-12, 25% of respondents reported that someone had offered, sold, or given them an illegal drug on school property

Statistic

Is the NUMERICAL value a Para/Stat? In a survey of 300 computer users, 8% said their computers had malfunctions that needed to be repaired by service technicians.

Statistic. 8% is a numerical description of a sample of computer users.

Is the NUMERICAL value a Para/Stat? A Survey of 1000 US adults found that 40% think that the Internet is the best way to get news and information.

Statistic. The 40% is a numerical description of a sample of US adults.

Is the NUMERICAL value a Para/Stat? A survey of 733 small business owners found that 17% have a current job opening.

Statistic. The value 17% is a numerical description of a sample of small business owners.

Is the NUMERICAL value a Para/Stat? A survey of 1004 US adults found that 52% think that China's emergence as a world power is a major threat to the well-being of the US.

Statistic. The value 52% is a numerical description of a sample of US adults.

What science is the collecting, organizing, analyzing, and interpreting data in order to make decisions?

Statistics

Choose the correct definition of Statistics

Statistics is the science of collecting, organizing, summarizing, and analyzing information to draw a conclusion and answer questions. In addition, statistics is about providing a measure of confidence in any conclusions.

What is statistics?

Statistics is the science of collecting, organizing, summarizing, and analyzing information to draw conclusions or answer questions. In addition, statistics is about providing a measure of confidence in any conclusions.

To determine her body temperature, Denise divides up her day into three parts: morning, afternoon, and evening. She then measures her body temperature at 3 randomly selected times during each part of the day. What type of sampling is used?

Stratified

At University XYZ, ten students were randomly selected from each of the 15 sections of College Algebra and were asked about the quality of the textbook used in the course.

Stratified Sample (because the population is divided into 15 differenct subgroup, they share similar characteristics and ten students were dandomly

Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below. A manman experienced a tax audit. The tax department claimed that the manman was audited because hehe waswas randomlyrandomly selectedselected fromfrom allall menmen inin hishis ageage group.group. nothing Which type of sampling did the tax department​ use?

Stratified sampling

ID the sampling technique: Soybeans are planted on a 48-acre field. The field is divided into one-acre subplots. A sample is taken from each subplot to estimate the harvest.

Stratified sampling is used because a sample is taken fromm each one-acre subplot.

Which sampling method subdivides the population into categories sharing similar characteristics and then selects a sample from each​ subdivision?

Stratified sampling method involves subdividing the population and uses a sample of members from each subdivision of the population. Next Question

ID the sampling technique: Opinion of students on stem cell research. You divide the student population with respect to majors and randomly select and question some students in each major.

Students are divided into a strata (majors) and a sample is selected from each major - Stratified sample

Stratified Sampling

Subdivide the population into two or more different subgroups (or strata) so that subjects within the same subgroup share the same characteristic (such as political affiliation, age, gender or ethnicity). Then we draw a random sample from each subgroup or stratum

Experimental Units

Subjects in an experiment

ID the sampling technique: A journalist goes to a campground to ask people how they feel about air pollution

Systematic sampling, because every tenth machine part is sampled.

There are several ways of collecting data - S/S People investigating by interviewing, checking Facebook, calling their BFF, or mailing a payment.

Survey: -Investigation of 1/more charac's of a population -Carried out by people asking questions -MC types are done by interview, internet, phone, or mail -When designing DON'T use leading questions, results in bias.

Sample standard deviation on TI 83+ is

Sx

Sample variance on TI 83+ is

Sx squared

Identify the type of sampling​ used: random,​ systematic, convenience,​ stratified, or cluster. To estimate the percentage of defects in a recent manufacturing​ batch, a quality control manager at General ElectricGeneral Electric selects every 1919th refrigeratorrefrigerator that comes off the assembly line starting with the tenthtenth until she obtains a sample of 8080 refrigeratorsrefrigerators. Which type of sampling is​ used?

Systematic

To estimate the percentage of defects in a recent manufacturing batch, a quality control manager at Ford selects every 15th truck that comes off the assembly line starting with the tenth until she obtains a sample of 60 trucks. What type of sampling is used?

Systematic

dentify the type of sampling​ used: random,​ systematic, convenience,​ stratified, or cluster. To estimate the percentage of defects in a recent manufacturing​ batch, a quality control manager at MicrosoftMicrosoft selects every 1818th software CDsoftware CD that comes off the assembly line starting with the sixthsixth until she obtains a sample of 120120 software CDssoftware CDs.

Systematic

dentify the type of sampling​ used: random,​ systematic, convenience,​ stratified, or cluster. To estimate the percentage of defects in a recent manufacturing​ batch, a quality control manager at ToshibaToshiba selects every 1313th laptoplaptop that comes off the assembly line starting with the thirdthird until she obtains a sample of 130130 laptopslaptops. Which type of sampling is​ used?

Systematic

Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below. A manman is selected by a marketing company to participate in a paid focus group. The company says that the manman was selected because everyevery 5000 th5000th personperson inin thethe phonephone numbernumber listingslistings waswas beingbeing selected.selected. Which type of sampling did the marketing company​ use?

SystematicSystematic sampling

Identify the type of sampling​ used: random,​ systematic, convenience,​ stratified, or cluster. To estimate the percentage of defects in a recent manufacturing​ batch, a quality control manager at MicrosoftMicrosoft selects every 2020th software CDsoftware CD that comes off the assembly line starting with the eightheighth until she obtains a sample of 120120 software CDssoftware CDs.

Systemic

dentify the type of sampling​ used: random,​ systematic, convenience,​ stratified, or cluster. To estimate the percentage of defects in a recent manufacturing​ batch, a quality control manager at IBMIBM selects every 1313th computercomputer that comes off the assembly line starting with the secondsecond until she obtains a sample of 110110 computerscomputers.

Systemic

The Gallup Organization contacts 1183 teenagers who are 13 to 17 years of age and live in the United States and asks whether or not they had attended a concert this past year. What is the population in the study? What is the sample in the study?

Teenagers who are 13 to 17 years of age and live in the United States. The 1183 teenagers who are 13 to 17 years of age and live in the United States.

A polling organization contacts 1294 teenagers who are 16 to 19 years of age and live in North America and asks whether or not they had driven a car on a highway recently. What is the population in the​ study?

Teenagers who are 16 to 19 years of age and live in North America.

Quantitative

That is or may be estimated by quantity. Of or relating to the describing or measuring of quantity. Quantitative variables provide numerical measure of individuals and can be added or subtracted and provide meaningful results.

A polling organization contacts 1294 teenagers who are 16 to 19 years of age and live in North America and asks whether or not they had driven a car on a highway recently. What is the sample in the study?

The 1294 teenagers who are 16 to 19 years of age and live in North America.

A​ quality-control manager randomly selects 60 bottles of soda that were filled on June 14 to assess the calibration of the filling machine. What is the sample in the study?

The 60 bottles of soda selected in the plant on June 14.

What is another factor that can affect experimental results?

The Placebo Effect: When subjects react favorably when no Tx has been prescribed.

What can be used to help control the placebo effect?

The blinding technique - where subject don't know if they are receiving a Tx or placebo. In a double-blind experiment, both the experimenter nor the subject know if they are receiving Tx or placebo.

Describe the data and LOM: HR (bpm) of an athlete during an exercise session.

The data is the collection of HRs, at the Ratio level because the data can be ordered, meaningful differences can be calculated, the data can be written as a ratio, and the data set contains an inherent zero.

Describe the data and LOM: BODY TEMPS! (F) of an athlete during an exercise session.

The data is the collection of body temps and is at the interval LOM because the data can be ordered and meaningful difference can be calculated, but it doesn't make sense to write a ratio using the temps.

Population

The entire group of individuals to be studied is called the population. An individual is a person or object that is a member of the population being studied.

Population?

The entire group of individuals to be studied is the population.

What dictates the best way to collect data?

The focus of the study.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Placements of swimmers in a swim meetPlacements of swimmers in a swim meet Choose the correct level of measurement.

The four levels of measurement are summarized as​ follows: Nominal Categories​ only; data cannot be arranged in an ordering scheme. Ordinal Categories are​ ordered, but differences cannot be found or are meaningless. Interval Differences are​ meaningful, but there is no natural zero starting point and ratios are meaningless. Ratio There is a natural zero starting point and ratios are meaningful. ORDINAL

Determine whether the given description corresponds to an observational study or an experiment. In a study of 381381 girlsgirls with a particular​ disease, the subjects were injected with vitamins towere injected with vitamins to determine if the vitamins have an effect on the disease.determine if the vitamins have an effect on the disease. Does the given description correspond to an observational study or an​ experiment?

The given description corresponds to an experimentan experiment.

Determine whether the given description corresponds to an observational study or an experiment. In a study of 359359 womenwomen with a particular​ disease, the subjects were monitored with an EEGwere monitored with an EEG while asleep.while asleep. Does the given description correspond to an observational study or an​ experiment?

The given description corresponds to an observational studyan observational study.

Determine whether the given description corresponds to an observational study or an experiment. In a study of 408408 womenwomen with a particular​ disease, the subjects were monitored with an EEGwere monitored with an EEG while asleep.

The given description corresponds to an observational studyan observational study.

Determine whether the given description corresponds to an observational study or an experiment. In a study of 443443 menmen with a particular​ disease, the subjects were photographed daily.were photographed daily. nothing Does the given description correspond to an observational study or an​ experiment?

The given description corresponds to an observational studyan observational study.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate for the data below. Years in which an Olympics was heldYears in which an Olympics was held Choose the correct answer below.

The intervalinterval level of measurement is most appropriate because the data can becan be ordered commaordered, differences left parenthesis obtained by subtraction right parenthesisdifferences (obtained by subtraction) can becan be foundfound and areand are meaningful commameaningful, and thereand there is nois no naturalnatural startingstarting zerozero point.

Which level of measurement consists of categories only where data cannot be arranged in an ordering​ scheme?

The nominal level of measurement is characterized by data that consist of​ names, labels, or categories only. The data cannot be arranged in an ordering scheme​ (such as low to​ high).

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Types of restaurants left parenthesis fast food comma organic food comma sea food comma etc. right parenthesisTypes of restaurants (fast food, organic food, sea food, etc.) Choose the correct answer below.

The nominalnominal level of measurement is most appropriate because data cannotdata cannot be arrangedbe arranged in an ordering schemein an ordering scheme.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate for the data below. Flight numbers

The nominalnominal level of measurement is most appropriate because the data cannotcannot bebe ordered.ordered. nothing nothing nothing nothing nothing nothing nothing nothing nothing

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate for the data below. Car models

The nominalnominal level of measurement is most appropriate because the data cannotcannot bebe ordered.ordered. nothing nothing nothing nothing nothing nothing nothing nothing nothing nothing

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate for the data below. Types of movies left parenthesis drama comma comedy comma adventure comma documentary comma etc. right parenthesisTypes of movies (drama, comedy, adventure, documentary, etc.) Choose the correct answer below.

The nominalnominal level of measurement is most appropriate because the data cannotcannot bebe ordered.ordered. nothing nothing nothing nothing nothing nothing nothing nothing nothing nothing

Which of the following consists of discrete​ data?

The number of suitcases on a plane is a number representing a count. This would consist of discrete data.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Critic ratings of movies on a scale from 1 star to 7 stars.Critic ratings of movies on a scale from 1 star to 7 stars. Choose the correct answer below.

The ordinalordinal level of measurement is most appropriate because categories are ordered commacategories are ordered, but differencesbut differences cannot be found or are meaninglesscannot be found or are meaningless.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Ranks of cars evaluated by a consumer's magazine.Ranks of cars evaluated by a consumer's magazine. Choose the correct answer below.

The ordinalordinal level of measurement is most appropriate because categories are ordered commacategories are ordered, but differencesbut differences cannot be found or are meaninglesscannot be found or are meaningless.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Ratings of hotels on a scale from 0 stars to 4 stars.Ratings of hotels on a scale from 0 stars to 4 stars. Choose the correct answer below.

The ordinalordinal level of measurement is most appropriate because categories are ordered commacategories are ordered, but differencesbut differences cannot be found or are meaninglesscannot be found or are meaningless.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Ratings of hotels on a scale from 0 stars to 7 stars.Ratings of hotels on a scale from 0 stars to 7 stars. Choose the correct answer below.

The ordinalordinal level of measurement is most appropriate because categories are ordered commacategories are ordered, but differencesbut differences cannot be found or are meaninglesscannot be found or are meaningless.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate for the data below. Alert system of yellow left parenthesis lowest right parenthesis comma orange comma and red left parenthesis highest right parenthesis

The ordinalordinal level of measurement is most appropriate because the data can becan be ordered commaordered, butbut differences left parenthesis obtained by subtraction right parenthesisdifferences (obtained by subtraction) cannotcannot be foundbe found or areor are meaningless.meaningless. nothing nothing

For a deeper understanding of a population, consider a market researcher for a soft drink company who might want to determine the sweetness preferences of Americans between the ages of 15 and 25. What is the population?

The population in this example includes ALL Americans in this age group.

Sample

The sample is a subset of the population that is being studied.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate for the data below. Brain volumes measured in cubic cmBrain volumes measured in cubic cm Choose the correct answer below.

The ratioratio level of measurement is most appropriate because the data can becan be ordered commaordered, differencesdifferences can becan be foundfound and areand are meaningful commameaningful, and thereand there is ais a naturalnatural startingstarting zerozero point.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate for the data below. Car lengths measured in feet

The ratioratio level of measurement is most appropriate because the data can becan be ordered commaordered, differencesdifferences can becan be foundfound and areand are meaningful commameaningful, and thereand there is ais a naturalnatural startingstarting zerozero point.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate for the data below. Car lengths measured in feetCar lengths measured in feet Choose the correct answer below.

The ratioratio level of measurement is most appropriate because the data can becan be ordered commaordered, differencesdifferences can becan be foundfound and areand are meaningful commameaningful, and thereand there is ais a naturalnatural startingstarting zerozero point.

A particular country has 4040 total states. If the areas of allof all 4040 states are added and the sum is divided by 4040​, the result is 207 comma 699207,699 square kilometers. Determine whether this result is a statistic or a parameter. Choose the correct answer below.

The result is a parameterparameter because it describes some characteristic of a populationpopulation

A particular country has 4545 total states. If the areas of allof all 4545 states are added and the sum is divided by 4545​, the result is 202 comma 196202,196 square kilometers. Determine whether this result is a statistic or a parameter.

The result is a parameterparameter because it describes some characteristic of a populationpopulation.

A particular country has 5555 total states. If the areas of allof all 5555 states are added and the sum is divided by 5555​, the result is 212 comma 072212,072 square kilometers. Determine whether this result is a statistic or a parameter. Choose the correct answer below. A.

The result is a parameterparameter because it describes some characteristic of a populationpopulation. This is the correct answer.B.

A particular country has 4040 total states. If the areas ofof 2525 states are added and the sum is divided by 2525​, the result is 204 comma 608204,608 square kilometers. Determine whether this result is a statistic or a parameter. Choose the correct answer below.

The result is a statisticstatistic because it describes some characteristic of a samplesample.

A particular country has 6060 total states. If the areas ofof 2020 states are added and the sum is divided by 2020​, the result is 179 comma 532179,532 square kilometers. Determine whether this result is a statistic or a parameter. Choose the correct answer below.

The result is a statisticstatistic because it describes some characteristic of a samplesample.

The data on the right relate to setups A through E of widescreen high-definition televisions. Setup | Size (in) | Screen Type | Number of Channels Available A | 60 | Plasma | 298 B | 42 | Projection | 105 C | 40 | Projection | 422 D | 58 | Projection | 270 E | 45 | Projection | 289 Identify the individuals, variables, and data corresponding to the variables. Determine whether each variable is qualitative, continuous, or discrete. What are the individuals being studied? What are the variables and their corresponding data being studied? Size is a ____ variable. Screen type is a ____ variable. Number of channels available is a ____ variable.

The setups A through E of widescreen high-definition televisions. Size (60, 42, 40, 58, 45), screen type (Plasma, Projection, Projection, Projection, Projection), and number of channels available (298, 105, 422, 270, 289) Continuous Qualitative Discrete

Determine whether the study depicts an observational study or an experiment. Fifty patients on aspirin are divided into two groups. One group is treated with a new anti-ulcer drug. The other is not. After one month, both groups are questioned about their stomach pain.

The study is an experiment because the researchers control one variable to determine the effect on the response variable.

Does the description correspond to an observational study or an experiment. Fifty patients with lung cancer are divided into two groups. One group receives an experimental drug to fight cancer, the other a placebo. After two years, the spread of the cancer is measured. Does the description correspond to an observational study or an experiment?

The study is an experiment because the researchers control one variable to determine the effect on the response variable.

Determine whether the study depicts an observational study or an experiment. A poll is conducted by a school's math department in which fourth-grade students are asked if they prefer to be in their math class or their English class.

The study is an observational study because the study examines individuals in a sample, but does not try to influence the response variable.

Determine whether the study depicts an observational study or an experiment. A survey is conducted asking 250 people, "Do you prefer soup A or soup B?"

The study is an observational study because the study examines individuals in a sample, but does not try to influence the response variable.

Determine whether the description below corresponds to an observational study or an experiment. In a studystudy sponsored by a​ company, 14 comma 66914,669 people were asked what contributes most to their sadness commasadness, and 36 %36% of the respondents said that it was their partner.partner. Is the study described above an observational study or an​ experiment?

The study is an observational study because the survey subjects were not given any treatment.

Determine whether the underlined value is a parameter or a statistic. One of the greatest baseball hitters of all time has a career batting average of 0.366. Is the value a parameter or a​ statistic?

The value is a parameter because the career at-bats of a baseball player are a population

Determine whether the value is a parameter or a statistic. The average score for a class of 28 students taking a calculus midterm exam was: 72 %.

The value is a parameter because the class of 28 students is a population

Determine whether the underlined value is a parameter or a statistic. Following the election, 18 % of the governors of all 50 areas of a country were female. Is the value a parameter or a​ statistic?

The value is a parameter because the governors of all 50 area of a country are a population.

Determine whether the underlined value is a parameter or a statistic. In a championship football game, a quarterback completed 59% of his passes for a total of 265 yards and 2 touchdowns. Is the value a parameter or a​ statistic?

The value is a parameter because the quarterback's passes are a population.

Determine whether the underlined value is a parameter or a statistic. In a survey of 1,011 people age 50 or older, *73%* agreed with the statement "I believe in life after death."

The value is a statistic because the 1,011 people age 50 or older are a sample.

Determine whether the underlined value is a parameter or a statistic. In a national survey on substance abuse, 66.4 % of respondents who were full-time college students aged 18 to 22 reported using alcohol within the past month. Is the value a parameter or a​ statistic?

The value is a statistic because the respondents who were full-time college students aged 18 to 22 are a samply

Determine whether the quantitative variable is discrete or continuous. Volume of liquid in a glass. Is the variable discrete or​ continuous?

The variable is continuous because it is not countable.

Determine whether the quantitative variable is discrete or continuous. Volume of water in a reservoir. Is the variable discrete or​ continuous?

The variable is continuous because it is not countable.

Determine whether the quantitative variable is discrete or continuous. Number of days of rainfall in a year. Is the variable discrete or​ continuous?

The variable is discrete because it is countable

Determine whether the quantitative variable is discrete or continuous. Touchdowns thrown by a quarterback. Is the variable discrete or​ continuous?

The variable is discrete because it is countable

Determine whether the quantitative variable is discrete or continuous. Number of lightning strikes in a city in one year.

The variable is discrete because it is countable.

Determine whether the quantitative variable is discrete or continuous. Number of pieces of lumber used to make a deck.

The variable is discrete because it is countable.

Determine whether the quantitative variable is discrete or continuous. Passes made by a defenseman in a hockey game.

The variable is discrete because it is countable.

Favorite Song

The variable is qualitative because it is a attribute characteristic

Favorite musical band

The variable is qualitative because it is an attribute characteristic

Determine whether the variable is qualitative or quantitative. Breed of cat. Is the variable qualitative or​ quantitative?

The variable is qualitative because it is an attribute characteristic.

Determine whether the variable is qualitative or quantitative. Zip code. Is the variable qualitative or​ quantitative?

The variable is qualitative because it is an attribute characteristic.

Determine whether the variable is qualitative or quantitative. Address

The variable is qualitative because it is an attribute classification.

Determine whether the variable is qualitative or quantitative. Street name of address.

The variable is qualitative because it is an attribute classification.

Age of car driver

The variable is quantitative because it is a numerical measure.

Determine whether the variable is qualitative or quantitative. Gallons of water in a swimming pool Is the variable qualitative or​ quantitative?

The variable is quantitative because it is a numerical measure.

Determine whether the variable is qualitative or quantitative. Height Is the variable qualitative or​ quantitative?

The variable is quantitative because it is a numerical measure.

Determine whether the variable is qualitative or quantitative. Number of cars owned. Is the variable qualitative or​ quantitative?

The variable is quantitative because it is a numerical measure.

Determine whether the variable is qualitative or quantitative. Amount of disk space in gigabytes.

The variable is quantitative because it is a numerical measure.

Number of cars owned

The variable is quantitative because it is a numerical measure.

Determine whether the source given below has the potential to create a bias in a statistical study. A certain medical organization tends to oppose the use of meat and dairy products in our​ diets, and that organization has received hundreds of thousands of dollars in funding from an animal rights foundation.

There does appear to be a potential to create a bias. There is an incentive to produce results that are in line with the​ organization's creed and that of its funders. In this​ case, there is a potential to create a bias because the medical organization could have an incentive to produce results favorable to its​ funder, the animal rights foundation. One should be very wary of a study in which the sponsor can somehow profit from the results because there is an incentive to produce biased results.

Suppose the percentage of all students on your campus that own a car is 48.2%. Is this a statistic or parameter?

This value represents a parameter because it is a numerical summary of a population.

Suppose a sample of 100 students is obtained, and from this sample we find that 46% own a car. is this a statistic or parameter ?

This value represents a statistic because it is a numerical summary of a sample.

What must a researcher be sure of when using sampling techniques?

To collect unbiased data, that heshe needs to make sure that sample is a representation of that population. This is to make appropriate inferential observation of the study.

A study conducted by researchers was designed "to determine if application of duct tape is as effective as cryotherapy in the treatment of common warts." The researchers randomly divided 50 patients into two groups. The 25 patients in group 1 had their warts treated by applying duct tape. The 25 patients in group 2 had their warts treated by cryotherapy. Once the treatments were complete, it was determined that 56% of the patients in group 1 and 66% of the patients in group 2 had complete resolution of their warts. The researchers concluded that cryotherapy is significantly more effective in treating warts than duct tape. Identify the research objective. Identify the sample. List the descriptive statistics. State the conclusion of the study.

To determine if duct tape is as effective as cryotherapy in treating warts. The 50 patients with warts. 56% of patients in group 1 and 66% of patients in group 2 with complete resolution. Cryotherapy is significantly more effective than duct tape in treating warts.

A news service conducted a survey of 1021 adults age 18 years or older in a certain country, August 31 - September 2, 2009. The respondents were asked, "Of every tax dollar that goes to the federal government, how many cents of each dollar would you say are wasted?" Of the 1021 individuals surveyed, 35% indicated that 51 cents or more is wasted. The new service reported that 35% of all adults in the country 18 years or older believe the federal government wastes at least 51 cents of each dollar spent, with a margin of error of 5% and a 90% level of confidence. What is the research objective? What is the population? What is the sample? List the descriptive statistics. What can be inferred from this survey?

To determine the proportion of adults in the country who believe the federal government wastes 51 cents or more of every dollar. Adults in the country aged 18 years or older. The 1021 adults in the country that were surveyed. Of the 1021 individuals surveyed, 35% indicated that 51 cents or more is wasted. The news service is 90% certain that the percentage of all adults in the country who believe the federal government wastes 51 cents or more of every dollar received is between 30% and 40%.

What is the goal of learning​ statistics?

To learn to distinguish between statistical conclusions that are likely to be valid and those that are seriously flawed Statistics is the science of planning studies and​ experiments, obtaining​ data, and then​ organizing, summarizing,​ presenting, analyzing,​ interpreting, and drawing conclusions based on the data. Statisticians universally agree that statistical thinking is​ good, but there are different views of what actually constitutes statistical thinking. Statistical thinking involves critical thinking and the ability to make sense of results. Statistical thinking might involve determining whether results are statistically significant.

Inferences based on voluntary response samples are generally not reliable. True or false

True, because I is often the case that the individuals who volunteer do not accurately represent the group.

Suppose three different individuals conduct the same statistical​ study, such as estimating the average commute time of students at a college. It is possible that all three studies end up with different results

True. Statistical studies typically look at samples rather than entire populations. Since each study is likely to draw different​ samples, it is quite possible that each study ends up with different​ results, due to variability in the data

Continuous

Uninterrupted in time; without cessation. A continuous variable is a quantitative variable that has an infinite number of possible values that are not countable.

Which of the following is NOT a misuse of​ statistics?

Utilizing valid statistical methods and correct sampling techniques Whether conducting a statistical analysis of data that we have​ collected, or analyzing a statistical analysis done by someone​ else, we should not rely on blind acceptance of mathematical calculations. We should consider the factors below. bullet• Context of the data bullet• Source of the data bullet• Sampling method bullet• Conclusions bullet• Practical implications When doing​ so, it is important to utilize valid statistical methods and correct sampling techniques. Next Question

____ are the characteristics of the individuals of the population being studied.

Variables

In a survey of 109 subjects, each was asked to indicate how many texts messages they send and receive each day. THe sample consisted of those who chose to respond to the request posted on the Stat Crunch Wed Site.

Voluntary Response Sample

Sampling Methods

Voluntary Response Sample Simple Random Sample Random Sample Systematic Sampling Convenience Sampling Stratified Sampling Cluster Sampling

Experiment

We apply some treatment and then proceed to observe its effects on the subjects

Observational Studies

We observe and measure specific characteristics, but we don't attempt to modify the subjects being studied

Random sample:

When -every member of A POPULATION (ALL - has an -equal chance- of being selected. Population: -A collection of ALL outcomes, responses, measurements, or counts that are of interest. -Represents ALL possible measurements or outcomes that are of interest to us in a particular study. -An ENTIRE set of individuals or objects, which may by finite or infinite.

Convenience sample

When individuals in a sample were easily obtained not based on any element of randomness but by ease of access to the researcher.

What should you use a stratified sample?

When its important for the sample to have members from each SEGMENT of the POPULATION. Here, members are divided into two or more subsets called -strata- that share a SIMILAR CHARAC like age, gender, ethnicity, or even political preference. Each segment of the population is represented. Like using socioeconomic status as divider.

Bias def.

When the results of a sample are not representative of the population or it's true feelings

The population of ages at inauguration of all U.S. Presidents who had professions in the military is​ 62, 46,​ 68, 64, 57. Why does it not make sense to construct a histogram for this data​ set?

With a data set that is so​ small, the true nature of the distribution cannot be seen with a histogram.

The population of ages at inauguration of all U.S. Presidents who had professions in the military is​ 62, 46,​ 68, 64, 57. Why does it not make sense to construct a histogram for this data​ set? Choose the correct answer below.

With a data set that is so​ small, the true nature of the distribution cannot be seen with a histogram.

The population of ages at inauguration of all U.S. Presidents who had professions in the military is​ 62, 46,​ 68, 64, 57. Why does it not make sense to construct a histogram for this data​ set?

With a data set that is so​ small, the true nature of the distribution cannot be seen with a histogram. Your answer is correct.C.

If it's NOT acceptable to have a same member selected more than once from a population:

Without replacement

n a​ graph, if one or both axes begin at some value other than​ zero, the differences are exaggerated. This bad graphing method is known as a nonzero axis.

X Nice Work! Using an axis that does not begin at zero can create an incorrect impression that small differences are substantial.

In a study of a weight loss​ program, 4545 subjects lost a mean of 3.13.1 lbs after 12 months. Methods of statistics can be used to show that if this diet had no​ effect, the likelihood of getting these results is roughly 1010 chances in 1000. Does the weight loss program have statistical​ significance? Does the weight loss program have practical​ significance?

Yes, because the results are unlikely to occur by chance. No, someone starting a weight loss program would likely want to lose considerably more than 2.42.4 lb.

Determine whether the value is from a discrete or continuous data set. Amount of fabric needed for a dress is 2.5 ydsAmount of fabric needed for a dress is 2.5 yds Is the value from a discrete or continuous data​ set?

You answered DiscreteDiscrete. The correct answer is ContinuousContinuous because the value for the "amount of fabric needed for a dress""amount of fabric needed for a dress" is one of infinitely many possibleone of infinitely many possible valuesvalues and thoseand those values cannot be counted.

Determine whether the value is from a discrete or continuous data set. Weight of gravel in a pile is 120 lbWeight of gravel in a pile is 120 lb Is the value from a discrete or continuous data​ set? Continuous

You answered DiscreteDiscrete. The correct answer is ContinuousContinuous because the value for the "weight of gravel in a pile""weight of gravel in a pile" is one of infinitely many possibleone of infinitely many possible valuesvalues and thoseand those values cannot be counted.

data

a fact or proposition used to draw a conclusion or make a decision. it describe characteristics of an individual

Qualitative, or categorical, variables

allow for classification of individuals based on some attribute or characteristic.

What is a case-control study?

an observational study that is retrospective, and individuals will be organized into homogeneous groups (similar characteristics and demographics) and asked about events in the past, and answers will be compared with homogeneous groups with opposite explanatory variables, like smokers compared with non-smokers.

Variables

are the characteristics of the individuals within the population.

Determine whether the given value is a statistic or a parameter. Upper A sample of employees is selected and it is found that 65 % own a computer.A sample of employees is selected and it is found that 65% own a computer. Choose the correct statement below

because the value is a numerical measurement describing a characteristic of a samplesample.

Qualitative

categorical, variables allow for classification of individuals based on some attribute or characteristic.

Descriptive statistics

consists of organizing and summarizing data. Descriptive statistics describe data through numerical summaries, tables, and graphs.

Determine whether the value is from a discrete or continuous data set. Time to learn a song is 4 hoursTime to learn a song is 4 hours Is the value from a discrete or continuous data​ set?

continuous

determine whether the quantitative variable is discrete or continuous Length (in minutes) of a country song

continuous

determine whether the quantitative variable is discrete or continuous Temperature on a randomly selected day in Memphis, Tennessee

continuous

Determine whether the given description corresponds to an observational study or an experiment. In a study of 420420 menmen with a particular​ disease, the subjects were injected with vitamins towere injected with vitamins to determine if the vitamins have an effect on the disease.determine if the vitamins have an effect on the disease. Does the given description correspond to an observational study or an​ experiment?

he given description corresponds to an experimentan experiment.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Ages of children: 3 comma 4 comma 5 comma 6 comma and 7Ages of children: 3, 4, 5, 6, and 7 Choose the correct answer below.

he nominal level of measurement is characterized by data that consist of​ names, labels, or categories only. Data are at the ordinal level of measurement if they can be arranged in some order. The interval level of measurement is like the ordinal​ level, with the additional property that the difference between any two data values is meaningful. The ratio level of measurement is the interval level with the additional property that there is also a natural zero starting point.

ratio level of measurement

if it has the properties of the interval level of measurement and the ratios of the values of the variable have meaning. A value of zero in the ratio level of measurement means the absence of the quantity. Arithmetic operations such as multiplication and division can be performed on the values of the variable.

ordinal level of measurement

if it has the properties of the nominal level of measurement and the naming scheme allows for the values of the variable to be arranged in a ranked or specific order.

interval level of measurement

if it has the properties of the ordinal level of measurement and the differences in the values of the variable have meaning. A value of zero in the interval level of measurement does not mean the absence of the quantity. Arithmetic operations such as addition and subtraction can be performed on values of the variable.

ordinal level of measurement

if it has the properties of the ordinal level of measurement and the differences in the values of the variable have meaning. A value of zero in the interval level of measurement does not mean the absence of the quantity. Arithmetic operations such as addition and subtraction can be performed on values of the variable.

nominal level of measurement

if the values of the variable name, label, or categorize. In addition, the naming scheme does not allow for the values of the variable to be arranged in a ranked or specific order.

A(n)_____________ is a person or object that is a member of the population being studied

individual

Non-response bias

individual selected to be in the sample who do not respond feel differently from those who do respond

discrete variable

is a quantitative variable that has either a finite number of possible values or a countable number of possible values. The term countable means that the values result from counting, such as 0, 1, 2, 3, and so on.

A discrete variable

is a quantitative variable that has either a finite number of possible values or a countable number of possible values. The term countable means that the values result from counting, such as 0,1,2,3, and so on. A discrete variable cannot take on every possible value between any two possible values.

sample

is a subset of the population that is being studied.

Statistics

is the science of collecting, organizing, summarizing, and analyzing information to draw or answer questions. In addition, statistics is about providing a measure of confidence in any conclusions.

descriptive statistic

it describes the results of the sample without making any general conclusions about the population consist of organizing and summarizing data. describe data through numerical summaries, tables, and graphs.

The standard deviation is used in conjunction with the ____ to numerically describe distributions that are bell shaped The ____ measures the center of the distribution, while the standard deviation measures the ____ of the distribution.

mean; mean; spread

Which measure of central tendency best describes the weight of the candy?

median because the data is skewed mean is useful when the data is symmetrical

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. States in a regionStates in a region Choose the correct level of measurement.

nominal

Statistic

numerical measurement describing some characteristic of a sample

Data can be

numerical, as in height, or nonnumerical, as in gender

Validity

of a variable or measurement represents how close to the true value the measurement is. In other words, a variable is valid if it measures what it is supposed to measure.\

Reliability

of a variable or measurement represents the ability of different measurements of the same individual to yield the same results

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Positions of runners in a racePositions of runners in a race Choose the correct level of measurement.

ordinal

determine the level of measurement of each variable. Highest degree conferred (high school, bachelor's, and so on)

ordinal

What are descriptive statistics?

organizing and summarizing the data, describing the data through summaries, tables and graphs.

Population standard deviation on TI 83+ is

ox

Population variance on TI 83+ is

ox squared

A(n) ____ is a numerical summary of a population.

parameter

determine whether the underlined value is a parameter or a statistic. Batting Average Ty Cobb is one of Major League Baseball's greatest hitters of all time, with a career batting average of 0.366

parameter

determine whether the underlined value is a parameter or a statistic. State Government Following the 2006 national midterm election, 18% of the governors of the 50 United States were female.

parameter

Quantitative variables

provide numerical measures of individuals. Arithmetic operations such as addition and subtraction can be performed on the values of a quantitative variable and will provide meaningful results.

Quantitative variables

provide numerical measures of individuals. The values of a quantitative variable can be added or subtracted, and provide meaningful results.

classify the variable as qualitative or quantitative. Nation of origin

qualitative

classify the variable as qualitative or quantitative. Phone number

qualitative

classify the variable as qualitative or quantitative. Grams of carbohydrates in a doughnut

quantitative

classify the variable as qualitative or quantitative. Number of unpopped kernels in a bag of ACT microwave popcorn

quantitative

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Voltage measurements of batteries: 1.5 Upper V comma 3 Upper V comma 4.5 Upper V comma 6 Upper V comma and 7.5 Upper VVoltage measurements of batteries: 1.5 V, 3 V, 4.5 V, 6 V, and 7.5 V Choose the correct answer below.

ratio

non-sampling errors

result from undercovery, non-response bias, response bias, or data entry errors

Cluster sample

selecting all individuals within a randomly selected collection or group of individuals. So selecting a randomly selected cluster unit, like certain random online classes, and collecting data on ALL of the population of that randomly selected cluster

Stratified Sample

separate population into non-overlapping groups and THEN obtain a simple sample of each group. (first separate into non-overlapping groups, then simple sample)

The distribution of violent crime is ____

skewed right

Simple Random sample

take a simple size n ("lower case + sample, upper case is population) from a large population size N, where every possible simple size n has an equally likely chance of occurring to every other possible size n

Anecdotal means

that the information being conveyed is based on casual observation, not scientific research

_x < M when

the histogram is skewed left

_x > M when

the histogram is skewed right

_x = M when

the histogram is symmetrical

The type of variable (qualitative, discrete, or continuous) dictates

the methods that can be used to analyze the data.

What is a cohort study?

these are prospective observational studies, meaning they look towards the future over a long period of observation. The studied individual will naturally get exposed to other variables (not intentionally by the researcher's hand) and then at the end of the study period the values of the response variables would be recorded. This is the most powerful and comprehensive form of observational studies.

Inferential statistics

uses methods that take a result from a sample, extend it to the population, and measure the reliability of the result.

What is the response variable?

weather or not what we are trying to study happened? e.g. in an experiment of whether or not radio waves cause brain tumors, whether or not brain tumors were contracted would be the response variable

Response bias

when answers in a study or survey don't reflect the true feelings of the respondents

When are populations under-represented?

when it's proportionally smaller in a sample than it truly is in the population

Sample bias

when the method used for selection, tends to favor certain individuals

How do you correctly infer results from a statistical study onto a population with 90% confidence of a 3% margin of error on a 34% statistical figure?

with 34%, there would be a 90% confidence level that the statistical figure is in between 31% and 37% - the margin of error can usually be either greater or smaller than originally expected, and they are 90% confident in that range for the studied statistic