BUAL FINAL all HW

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Consider a normal population with a mean of 10 and a variance of 4. Find P(X ≥ 10).

.50

As the sample size n increases, the width of the confidence interval ________.

decreases stays the same increases

T/F Errors of non-observation occur when data values are recorded incorrectly.

false

The company financial officer was interested in the average cost of PCs that had been purchased in the past six months. She took a random sample of the price of 10 computers, with the following results.$3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000What is the third quartile?

$3,449.00

What is the probability that a standard normal random variable will be between .3 and 3.2?

.3814

Which of the following correlation coefficients describes the strongest relationship between two quantitative variables?

- 0.80 0.25 1.29 0.85

Given that the length an athlete throws a hammer is a normal random variable with mean 50 feet and standard deviation 5 feet, what is the probability he throws it between 50 feet and 60 feet?

.4772

Consider a normal population with a mean of 10 and a variance of 4. Find P(X > 18).

.00

The flying time of a drone airplane has a normal distribution with mean 4.76 hours and standard deviation of .04 hours. What is the probability that the drone will fly less than 4.66 hours?

.0062

Consider a normal population with a mean of 10 and a variance of 4. Find P(X < 6).

.0228

The weight of a product is normally distributed with a mean of 4 ounces and a variance of .25 squared ounces. What is the probability that a randomly selected unit from a recently manufactured batch weighs more than 5 ounces?

.0228

The population of lengths of aluminum-coated steel sheets is normally distributed with a mean of 30.05 inches and a standard deviation of .2 inches. What is the probability that a sheet selected at random will be less than 29.75 inches long?

.0668

Consider the following data on distances traveled by people to visit the local amusement park and calculate the relative frequency for the distances over 24 miles.

.125 .375 .325 .025 .150

The population of lengths of aluminum-coated steel sheets is normally distributed with a mean of 30.05 inches and a standard deviation of .2 inches. What is the probability that a sheet selected at random from the population is between 30.25 and 30.65 inches long?

.1574

Given that the length an athlete throws a hammer is a normal random variable with mean 50 feet and standard deviation 5 feet, what is the probability he throws it no less than 55 feet?

.1587

The flying time of a drone airplane has a normal distribution with mean 4.76 hours and standard deviation of .04 hours. What is the probability that the drone will fly more than 4.80 hours?

.1587

The internal auditing staff of a local lawn-service company performs a sample audit each quarter to estimate the proportion of accounts that are delinquent (more than 90 days overdue). For this quarter, the auditing staff randomly selected 400 customer accounts and found that 80 of these accounts were delinquent. What is the 95 percent confidence interval for the proportion of all delinquent customer accounts at this company?

.1608 to .2392

Consider the following data on distances traveled by people to visit the local amusement park and calculate the relative frequency for the shortest distance.

.500 .375 .300 .150 .333

The weight of a product is normally distributed with a mean of 4 ounces and a variance of .25 squared ounces. What is the probability that a randomly selected unit from a recently manufactured batch weighs more than 3.75 ounces?

.6915

The following is a partial relative frequency distribution of grades in an introductory statistics course. Find the relative frequency for the B grade.

.78 .27 .47 .37 .65

Consider a normal population with a mean of 10 and a variance of 4. Find P(X > 7).

.9332

Probabilities must be assigned to sample space outcomes so that the probability assigned to each sample space outcome must be between ________, inclusive.

0 and 1

At the end of their final exam, 550 students answered an additional question in which they rated their instructor's teaching effectiveness, with the following results. What proportion of the students who rated their instructor as very or somewhat effective received a C or lower in the class?

0.15 0.10 0.03 0.06 0.13

Which of the following correlation coefficient describes the weakest relationship between two quantitative variables?

0.70 - 0.80 - 0.50 1.29 0.15

822 recently purchased books were randomly selected from all recent book purchases over the Internet. The chart below shows the breakdown of the classification of the book type. What percentage of the books in the sample were self-help books?

0.940 1.82 0.0182 .1144 11.44

The average lateness for one of the top airline companies is 10 minutes. The variance of the lateness measure is calculated as 9. An airplane arrived 13 minutes after the stated arrival time. Calculate the z-score for the lateness of this particular airplane.

1.00

The population of lengths of aluminum-coated steel sheets is normally distributed with a mean of 30.05 inches and a standard deviation of .2 inches. What is the probability that a sheet selected at random will be less than 31 inches long?

1.00

Find the z-score for an IQ test score of 118 when the mean is 100 and the standard deviation is 15.

1.2

Find the z-score for an IQ test score of 125 when the mean is 100 and the standard deviation is 15.

1.67

In a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66.What is the IQR?

10

The company financial officer was interested in the average cost of PCs that had been purchased in the past six months. She took a random sample of the price of 10 computers, with the following results.$3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000What are the lower and upper limits of a box-and-whiskers display of this data?

2541, 3903 2087, 4357 2768, 3676 1633, 2087 2314, 4130

In a statistics class, 10 scores were randomly selected with the following results (mean = 71.5): 74, 73, 77, 77, 71, 68, 65, 77, 67, 66.What is the range?

144.00 4.77 12.00 516.20

In a hearing test, randomly selected subjects estimate the loudness (in decibels) of a sound, and the results are (mean = 70): 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68.What is the standard deviation? (practice using Excel with commands given in class)

18 324 6.76 4.73 22.40

822 recently purchased books were randomly selected from all recent book purchases over the Internet. The chart below shows the breakdown of the classification of the book type. What percentage of the books in the sample were either mystery or science fiction/fantasy?

18.61 24.33 17.88 36.50 22.99

The company financial officer was interested in the average cost of PCs that had been purchased in the past six months. She took a random sample of the price of 10 computers, with the following results.$3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000What is the first quartile?

2,995

Find the z-score for an IQ test score of 142 when the mean is 100 and the standard deviation is 15.

2.8

In a hearing test, randomly selected subjects estimate the loudness (in decibels) of a sound, and the results are (mean = 70): 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68.What is the range?

22.40 324 4.73 6.76 18

Compute the population variance of these data: 16,18,23,21,17,16,24,23,9,17,11,16,22,10,15,14. (practice using Excel with commands given in class)

3.87 3.625 17.0 21.9 20.5

If the median of a data set is 760, the third quartile is 950, and the first quartile is 650, what is the interquartile range?

300

A normal population has 99.73 percent of the population measurements within ________ standard deviation(s) of the mean.

4 3 1 2

In a statistics class, 10 scores were randomly selected with the following results (mean = 71.5): 74, 73, 77, 77, 71, 68, 65, 77, 67, 66.What is the standard deviation? (practice using Excel with commands given in class)

4.77

In a statistics class, 10 scores were randomly selected with the following results (mean = 71.5): 74, 73, 77, 77, 71, 68, 65, 77, 67, 66.What is the range?

4.77 144.00 516.20 22.72 12.00

Personnel managers usually want to know where a job applicant ranked in his or her graduating class. With a grade point average of 3.83, Michelle Robinson graduated above the 93rd percentile of her graduating class. What is the percentile rank of a student whose GPA was the median GPA?

50th

In a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66.What are the lower and upper limits of a box-and-whiskers display of this data?

52, 92

In a statistics class, 10 scores were randomly selected, with the following results:74, 73, 77, 77, 71, 68, 65, 77, 67, 66.What is the 10th percentile?

65.5

In a statistics class, the following 10 scores were randomly selected: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66.What is the mode? (practice using Excel with commands given in class)

71.0 72.0 71.5 73.0 77.0

In a statistics class, the following 10 scores were randomly selected: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66.What is the median? (practice using Excel with commands given in class)

72.0 71.0 71.5 73.0

In a statistics class, the following 10 scores were randomly selected: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66.What is the mean? (practice using Excel with commands given in class)

73.0 72.0 71.5 71.0

in a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66.What is the 65th percentile?

74.0

Which percentile describes the third quartile, Q3?

75th

In a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66.What is the third quartile?

77.0

If the random variable x is normally distributed, ______ percent of all possible observed values of x will be within three standard deviations of the mean.

99.73

A multiple choice question on an exam has four possible responses—(A), (B), (C), and (D). When 250 students take the exam, 100 give response (A), 25 give response (B), 75 give response (C), and 50 give response (D). (a) Write out the frequency distribution, relative frequency distribution, and percent frequency distribution for these responses. (Round your relative frequency answers to 2 decimal places.) (b) Choose the bar chart for this data using frequencies.

A) (image) B) Figure A is correct Figure B is correct Figure C is correct

Lauren is a college sophomore majoring in business. This semester Lauren is taking courses in accounting, economics, management information systems, public speaking, and statistics. The sizes of these classes are, respectively, 375, 35, 45, 25, and 60. (a) Find the mean and the median of the class sizes. (b) What is a better measure of Lauren's "typical class size"—the mean or the median?

A) median- 45 mean- 108 B) median

Which of the following is a type of question used in survey research?

All of the other answers are correct. open-ended dichotomous multiple-choice

A commercial shipping company operates a large fleet of trucks. The company needs to collect data on vehicle usage including acceleration, braking, and vehicle maintenance such as fluid levels. The datasourcing method needed to collect the data for this scenerio is

Clickstream Point of Sale Sensor Social Media None of these

Which of the following describes the steps of the Analytic Process after we know the business problem?

Collect Descriptives-Ask the Next Question-Choose Sampling Method-Make Prediction Choose Sampling Method-Choose DataSourcing Method-Make Prediction-Ask Next Question None of these Choose DataSourcing Method-Collect Descriptives-Make Prediction-Ask Next Question Choose DataSourcing Method-Choose Sampling Method-Collect Descriptives-Make Prediction-Ask Next Question Collect Descriptives-Choose Sampling Method-Make Prediction-Ask Next Question

If we are concerned whether the data was collected confidentially or anonymously, this is an example of which data ethic principle?

Consent Currency Ownership Openness Privacy

The Data Ethics principle that supports datasets can be made available to the public is:

Consent Privacy Ownership Currency Openness

A local store wants to find out if a new item is linked by their customers. They ask the first 10 customers that enter the store and use only this data. This is an example of sampling.

Convenient Stratified Random Cluster Response Simple Random

What is the process of displaying large quantities of data in a meaningful way called?

Data Visualization None of these Big Data Visual Analytics

The question "Do you use third-party cookies" is an example of what would be asked if a person was concerned about:

Data Visualization Oppenness Storytelling Data Ethics

________ and ________ are used to describe qualitative (categorical) data.

Dot plots, bar charts Bar charts, pie charts Pie charts, histograms Stem-and-leaf displays, scatter plots Scatter plots, histograms

Which of the following are included in the Key Points of Storytelling?

Eliminate distorted axes Include slashes Choose the appropriate graph & tell an acurrate story Always include a title and data values

What is it called when we combine graphs (visuals) with predictive analytics?

Graphic Tabulations Storytelling None of these Data Visualization Visual Analytics

From the video we watched in class (the link is provided in the powerpoint in module Misleading Graphs), the act of choosing a portion of the axis which leads to telling a misleading story is called:

Informed Consent Biased Selection Openness Analytics Visualization Cherry Picking

Classify each of the following qualitative variables as ordinal or nominative.

Letter Grades: Ordinal - each grade from A to F indicates an increasingly lower grade. Door Choices: Nominative - each door is the same except for the number given. For example, Door 1 is not better or worse or higher or lower than Door 3. TV Classifications: Ordinal - each category from TV-G to TV-MA indicates programming appropriate for increasingly older viewers. PC Ownership: Nominative - no ordering of categories. Restaurant Ratings: Ordinal - each rating from 5-star to 1-star indicates an increasingly lower rating. Filing Status: Nominative - no ordering of categories.

In the Analytic Process, the next step after the descriptives (descriptives is the data that has occurred up to the current point in time) have been collected, is to use the data to:

Make predictions None of these Make an actionable decision Conduct a random sample Ask the next question

If Amazon wanted to ensure a customers' response to an online survey was confidential and the sampling method was unbiased, which of the following should be implemented?

Make sure those customers who volunteer to reply are coded with random identification number Use a means of distribution to ensure there is no identification to any of the participants Send an email to customers with only a first or last name in their userid but not both Identify each randomly selected customer by a random identification number

When a person gives an answer that they think you want to hear or is politically correct, this is an example of which bias:

Measurement Error Recording Error Undercoverage Undercoverage

Which of the following questions would result in Response Bias?

None of the questions would result in a bias Would you prefer to eat a steak or a peanut butter sandwich? Since hacking is so common, are you confident that the information you provide online is secure? What do you think is the best way to remove trash from our waterways? Would you attend a cooking demonstration?

If a dataset's maximum value is 1500 but the graph only goes to 1000, this is an example of:

None of these Data Ethics Data Analytics Ownership Misleading Graphs

________ occurs when some population elements are excluded from the process of selecting the sample.

Nonresponse Sample frame Undercoverage Error of observation

When a low response bias occurs, what should you do?

Nothing can be done to correct this bias Conduct a convenient sample Ask a different question Conduct another sample to increase the response rate Report whatever data was collected

A graphical portrayal of a quantitative data set that divides the data into classes and gives the frequency of each class is a(n) ________.

Pareto chart bar chart ogive plot dot plot histogram

A(n) ________ is a graphical presentation of the current status and historical trends of a business's key performance indicators.

Pareto chart histogram dashboard frequency distribution

When a company sells your data from a datasourcing method such as clickstream, this is an example of which data ethic principle?

Privacy Openness currency Ownership

Below we list several variables. Which of these variables are quantitative and which are qualitative?

Quantitative; dollar amounts correspond to values on the real number line. Quantitative; net profit is a dollar amount. Qualitative; which stock exchange is a category. Quantitative; national debt is a dollar amount. Qualitative; which type of medium is a category.

the 2020 Presidential Election was in November and we saw reports on the percentage of Americans who were registered to vote in the national. If we wanted to sample all registered to vote in the national election. If we wanted to sample all registered voters in the United States and avoid bias, as well as, save time and money, the appropriate sampling method to use would be:

Simple Random Sampling of registered voters Volunary Sampling by States Cluster Random Sampling by regions nationwide Stratified Random Sampling by States Systematic Random Sampling of registered voters

A doctor's office needs to know how many of their services are used by their patients during a one year time period. Before a patient leaves their office, a summary report includes the date, the doctor they saw, the services provided, and the total charge for each service. Which of the following datasourcing methods best describes this data collection scenario?

Survey Clickstream Observation Social Media Point of Sale None of these

StitchFix wants to make sure different specific characteristics, such as all different age groups, are represented in their sample. The appropriate sampling method they should use is:

Systematic Sampling Stratified Random Sampling Voluntary Sampling Cluster Sampling Simple Random Sampling

T/F Statistical inference is the science of using a sample of measurements to make generalizations about the important aspects of a population of measurements.

TRUE

Amazon collects random reviews from their customers on the West Coast as the data they use for their nationwide marketing plan. This sample suffers from which sampling bias?

Undercoverage Response Bias Nonresponse Error Recording Error

The state agriculture department tested 203 fuel samples across the state in 2009 for accuracy of the reported octane level. For premium grade, 14 out of 105 samples failed. Find a 99 percent confidence interval for the true population proportion of premium grade fuel-quality failures.

[.048, .219]

Recently, a case of food poisoning was traced to a particular restaurant chain. The source was identified, and corrective actions were taken to make sure that the food poisoning would not reoccur. Despite the response from the restaurant chain, many consumers refused to visit the restaurant for some time after the event. A survey was conducted three months after the food poisoning occurred, with a sample of 319 former customers contacted. Of the 319 contacted, 29 indicated that they would not go back to the restaurant because of the potential for food poisoning. Construct a 95 percent confidence interval for the true proportion of the market who still refuse to visit any of the restaurants in the chain three months after the event.

[.059, .122]

In 2005, 13,000 Internet users were surveyed and asked about their willingness to pay fees for access to websites. Of these, 2,938 were definitely not willing to pay such fees. Construct a 95 percent confidence interval for the proportion definitely unwilling to pay fees.

[.219, .233]

The success rate of an experimental medical procedure is 37 per 120 cases in a sample. Find a 95 percent confidence interval for the actual success proportion of the procedure.

[.2260, .3910]

In a randomly selected group of 650 automobile deaths, 180 were alcohol related. Construct a 95 percent confidence interval for the true proportion of all automobile accidents caused by alcohol.

[.243, .311]

A survey of the top 10 employees in a major Midwest city found workers spent an average of 413 minutes per day on a job with standard deviation = 26.8 minutes. If the time spent on the job is approximately normal, what are the times within which approximately 68% of all workers fall?

[386.2,439.8]

Which of the following is a quantitative variable?

a person's gender the manufacturer of a cell phone whether a person has a charge account mileage of a car

Thirteen internists in the Midwest are randomly selected, and each internist is asked to report last year's income. The incomes obtained are152,000 144,000 162,000 154,000 146,000241,000 127,000 141,000 171,000 177,000138,000 132,000 192,000 (a) Find the 90th percentile. (b) Find the median. (c) Find the first quartile. (d) Find the third quartile. (e) Find the 10th percentile. f) Find the interquartile range. (g-1) Develop a five-number summary. (g-2) Choose the box plot for this data.

a) 192,000 b) 152,000 c) 141,000 d) 171,000 e) 132,000 f) 30,000 g-1) image g-2) A

An example of manipulating a graphical display to distort reality is ________.

adding an unbiased caption making the bars in a histogram equal widths stretching the axes starting the axes at zero

A measurement located outside the upper limits of a box-and-whiskers display is ________.

always the largest value in the data set always in the first quartile an outlier within the lower limits

Which one of the following graphical tools is used with quantitative data?

bar chart histogram pie chart Pareto chart

The area under the curve of a valid continuous probability distribution must ________.

be infinite be less than 1 equal 1 be between 0 and 1

The proportion of measurements in a class is called the ________ of that class.

cumulative percentage relative frequency leaf frequency

The number of measurements falling within a class interval is called the ________.

cumulative sum relative frequency leaf frequency

Probabilities must be assigned to each sample space outcome so that the probabilities of all the sample space outcomes add up to ________.

between −1 and 1 between 0 and 1 0 1

A set of all elements we wish to study is called a ________.

census process sample population

The ________ of event X consists of all sample space outcomes that do not correspond to the occurrence of event X.

complement conditional probability dependence independence

The Data Ethics principle that ensures a participant is aware of what data is being collected, the purpose, and how the data will be used is _________. (one word answer)

consent

A normal distribution with mean equal to zero and a standard deviation equal to one is called the ________ normal distribution.

continuous uniform standard exponential

Given a scatterplot, if one quantitative variable increases when the other quantitative variable variable decreases, the _____ is _______. (one word per blank; separate word answers with a comma and no spaces. For example, answer1,answer2

direction, negative

Given a scatterplot, if one quantitative variable increases as the other quantitative variable increases, the _____ is _______. (one word per blank; separate word answers with a comma and no spaces. For example, answer1,answer2

direction, positive

Given that X is a normal random variable, the probability that a given value of X is below its mean is ________.

equal to .5 1 greater than .5 less than .5

The set of all possible outcomes for an experiment is called a(n) ________.

experiment event probability sample space

T/F Convenience sampling is a type of probability sampling in which we select elements to sample because we believe they have the highest probability of responding.

false

T/F A low response rate has no effect on the validity of a survey's findings.

false

T/F A quantitative variable can also be referred to as a categorical variable.

false

T/F A scatter plot can be used to identify outliers.

false

T/F An example of a qualitative variable is the mileage of a car.

false

T/F Business analytics is a new field that does not use traditional statistics to analyze big data.

false

T/F If the random variable, x, is normally distributed, 68.26 percent of all possible observed values of x will be within two standard deviations of the mean.

false

T/F If we examine some of the population measurements, we are conducting a census of the population.

false

T/F In order to select a stratified random sample, we divide the population into overlapping groups of similar elements.

false

T/F Range is a better measure of variation than standard deviation.

false

T/F The median is the measure of central tendency that divides a population or sample into four equal parts.

false

T/F The range of the measurement is the largest measurement plus the smallest measurement.

false

T/F When data are qualitative, the bars should never be separated by gaps.

false

Examining all population measurements is called ________.

frame variable sample census

A process of observation that has an uncertain outcome is referred to as a(n) ________.

frequency conditional probability experiment probability

The grade a student received on an examination was transformed to a z value, which was negative. Therefore, we know that he scored

higher than 16 percent of the class. above the first quartile. lower than 16 percent of the class. higher than 45 percent of the class. below the mean.

Which of the following divides quantitative measurements into classes and graphs the frequency, relative frequency, or percentage frequency for each class?

histogram stem-and-leaf display dot plot scatter plot

A ________ displays the frequency of each class with qualitative data and a ________ displays the frequency of each class with quantitative data.

histogram, stem-and-leaf display scatter plot, bar chart stem-and-leaf, pie chart bar chart, histogram

Which of the following is not an example of unethical statistical practices?

improper sampling inappropriate interpretation of statistical results descriptive measures that mislead the user None of the other answers is correct. using graphs to make statistical inferences

A(n) ________ variable is a qualitative variable such that there is no meaningful ordering or ranking of the categories.

interval nominative ordinal ratio

An identification of police officers by rank would represent a(n) ________ level of measurement.

interval nominative ratio ordinal

A person's telephone area code is an example of a(n) ________ variable.

interval ratio ordinal nominative

A(n) ________ variable can have values that indicate into which of several categories of a population it belongs.

interval ratio qualitative quantitative

in ________ we select elements because they are easy to sample.

judgment sampling random sampling convenient sampling probability sampling

Which of the following is influenced the least by the occurrence of extreme values in a sample?

median mean weighted mean geometric mean

The ________ is the positive square root of the sample variance.

median population standard deviation range sample standard deviation

If a population distribution is skewed to the right, then, given a random sample from that population, one would expect that the ________.

median would be less than the mean median would be greater than the mean median would be equal to the mean mode would be equal to the mean

The specific shape of each normal distribution is determined by its ________ and ________.

median, standard deviation mean, variance median, variance mean, standard deviation

Another name for the 50th percentile is the ________.

mode first quartile median third quartile mean

All of the following are measures of central tendency except the ________.

mode mean median range

If a population distribution is skewed to the right, then, given a random sample from that population, one would expect that the ________.

mode would be equal to the mean median would be less than the mean median would be equal to the mean median would be greater than the mean

A(n) ________ variable is a qualitative variable such that there is no meaningful ordering or ranking of the categories.

nominative ratio interval ordinal

A relative frequency histogram having a longer tail to the right than to the left is said to be ________.

normal a scatter plot skewed to the left skewed to the right

A relative frequency histogram having a longer tail to the right than to the left is said to be ________.

normal a scatter plot skewed to the right skewed to the left

The ________ of an event is a number that measures the likelihood that an event will occur when an experiment is carried out.

observation intersection probability outcome

Measurements from a population are called

observations. processes. elements. variables.

A plot that allows us to visualize the relationship between two variables is a(n) ________ plot.

ogive dot scatter frequency

The relationship between the standard normal random variable, z, and normal random variable, X, is that

only the standard normal variable z is continuous. only the normal random variable X is continuous. the standard normal variable z counts the number of standard deviations that the value of the normal random variable X is away from its mean. the values of the normal random variable X cannot be negative. the values of the standard normal random variable z cannot be negative.

A Yes or No question is ________.

open-ended dichotomous evaluative systematic

Possible qualitative data for Stitchfix to collect is a clothing size such as small, medium, and large. This is an example of __________ (ordinal, nominal, discrete, or continuous) variable.

ordinal

An identification of police officers by rank would represent a(n) ________ level of measurement.

ordinal interval ratio nominative

Classify each of the following qualitative variables as ordinal or nominative.

ordinal: selected answer Statistics course letter grade A B C D F, Television show classificationsTV-G TV-PG TV-14 TV-MA, Ordinal selected answer Restaurant rating***** **** *** ** * nominative: Door choice on Let's Make A DealDoor #1 Door #2 Door #3, selected answer Personal computer ownership Yes No, Income tax filing status Married filing jointly; Married filing separately; Single; Head of household; Qualifying widow(er)

Below we give the overall dining experience ratings (Outstanding, Very Good, Good, Average, or Poor) of 30 randomly selected patrons at a restaurant on a Saturday evening. (a) Find the frequency distribution and relative frequency distribution for these data. (Round your relative frequency answers to 3 decimal places.)

outstanding- 14 frequency, .467 relative frequency very good- 10, .333 good- 5, .167 average- 1, .033 poor- 0,0

A ________ shows the relationship between two variables.

pie chart histogram bar chart stem-and-leaf scatter plot

In ________ we select elements because they are easy to sample.

probability sampling random sampling convenience sampling judgment sampling

A ________ is a subset of the units in a population.

process variable sample census

A ________ variable takes on values that are numbers on the real number line.

quantitative categorical qualitative nominative

An unusually large or small observation separated from the rest of the data is a(n) ________.

quartile mode absolute extreme outlier

A ________ is a measure of the chance that an uncertain event will occur.

random experiment probability population complement sample space

The proportion of measurements in a class is called the ________ of that class.

relative frequency leaf cumulative percentage frequency

The ________ is the positive square root of the sample variance.

sample mean median range sample standard deviation population standard deviation

A(n) ________ is a collection of sample space outcomes.

set event probability experiment

if a histogram has a long left or right tail, the data is described as:

skewed Approximately Normal A story All of these

If the mean is greater than the median, then the relative frequency curve is most likely to be ________.

skewed right

If the mean is greater than the median, then the relative frequency curve is most likely to be ________.

skewed right skewed left symmetrical bimodal

A histogram that has a longer tail extending toward smaller values is ________.

skewed to the left a scatter plot skewed to the right normal

A histogram that has a longer tail extending toward smaller values is ________.

skewed to the right a scatter plot skewed to the left normal

If the mean, median, and mode for a given population are all equal and the relative frequency curve has matching tails to the right and left, then we would describe the shape of the distribution of the population as ________.

skewed to the right bimodal skewed to the left symmetrical

What should be included on a graph axis when the scale does not start at zero? (one word answer)

slashes

When developing a frequency distribution, the class (group) intervals must be ________.

small large equal integer nonoverlapping

Nonoverlapping groups of similar elements in a population are called

stages. clusters. strata. frames.

As the margin of error decreases, the width of the confidence interval ________.

stays the same increases decreases

StitchFix has 1000 customers they sampled by age. They should use _________ random sampling to randomly select 50 customers from each age group.

stratified

If the mean, median, and mode for a given population are all equal and the relative frequency curve has matching tails to the right and left, then we would describe the shape of the distribution of the population as ________.

symmetrical skewed to the right skewed to the left bimodal

By randomly selecting a starting point then choosing every 50th person, we are conducting a ________ random sample.

systematic

The fill weight of a certain brand of adult cereal is normally distributed with a mean of 910 grams and a standard deviation of 5 grams. We calculated the value of z for a specific box of this brand of cereal, and the z value was negative. This negative z value indicates that

the fill weight is more than 910 grams. we made a mistake in our calculations, as z must always be a nonnegative number. the fill weight is less than 910 grams. the fill weight may be more or less than 910 grams depending on the value of the standard deviation. the fill weight is equal to 910 grams.

When a confidence interval for a population proportion is constructed for a sample size n = 30 and the value of pˆp^ = .4, the interval is based on

the t distribution. the z distribution. the Poisson distribution. the exponential distribution. None of these answers is correct.

The purpose of collecting a random sample from a population is:

to replicate the population to create a census to ask the next question to make statistical inferences about the entire population

T/F A bar chart is a graphic that can be used to depict qualitative data.

true

T/F A common practice in selecting a sample from a large geographic area is multistage cluster sampling.

true

T/F A population is a set that includes all elements about which we wish to draw a conclusion.

true

T/F A random sample is selected so that every element in the population has the same chance of being included in the sample.

true

T/F A recording error is an error of observation.

true

T/F An analytic dashboard presents both current and historical trends of a business's key performance indicators.

true

T/F Beginning the vertical scale of a graph at a value different from zero can cause increases to look more dramatic.

true

T/F By taking a systematic sample in which we select every 100th shopper arriving at a specific store, we are approximating a random sample of shoppers

true

T/F For a continuous distribution, P(X ≤ 100) = P(X < 100).

true

T/F In any probability situation, either an event or its complement must occur.

true

T/F In systematic sampling, the first element is randomly selected from the first (N/n) elements.

true

T/F It is possible to use a random sample from a population to make statistical inferences about the entire population.

true

T/F Sampling error occurs because a characteristic of a random sample may not exactly equal the population characteristic that we are attempting to estimate.

true

T/F Stratification can at times be combined with multistage cluster sampling to develop an appropriate sample.

true

T/F The mean and median are the same for a normal distribution.

true

T/F The median is said to be resistant to extreme values.

true

T/F The median is the value below which and above which approximately 50 percent of the measurements lie.

true

T/F The mode is the measurement in a sample or population that occurs most frequently.

true

T/F The population mean is the average of the population measurements.

true

T/F The relative frequency is the frequency of a class divided by the total number of measurements.

true

T/F The z value tells us the number of standard deviations that a value, x, is from the mean.

true

T/F Using a nonrandom sample procedure in order to support a desired conclusion is an example of an unethical statistical procedure.

true

T/F When looking at the shape of the distribution using a histogram, a distribution is skewed to the right when the left tail is shorter than the right tail.

true

Which of the following is a categorical variable?

value of company stock air temperature whether a person has a traffic violation daily sales in a store

Which of the following is a quantitative variable?

whether a person is a college graduate whether a person has a charge account mileage of a car a person's gender the manufacturer of a cell phone

A standard normal distribution has a mean of ________ and standard deviation of ________.

zero, one


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