stat
What is a bar graph? What is a Pareto chart? Question content area bottom 1.What is a bar graph? 2.What is a Pareto chart?
1.A bar graph is a horizontal or vertical representation of the frequency or relative frequency of the categories. The height of each rectangle represents the category's frequency or relative frequency. 2.A Pareto chart is a bar graph whose bars are drawn in decreasing order of frequency or relative frequency.
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? 1.What is an observational study? 2.What is a designed experiment? 3.Which allows the researcher to claim causation between an explanatory variable and a response variable?
1.An observational study measures the value of the response variable without attempting to influence the value of either the response or explanatory variables. 2.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. 3.A designed experiment allows the researcher to claim causation between an explanatory variable and a response variable
1.Explain what is meant by confounding. What is a lurking variable? What is a confounding variable? 2.What is a lurking variable? 3.What is a confounding variable?
1.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. 2.A lurking variable is an explanatory variable that was not considered in a study, but that affects the value of the response variable in the study. In addition, lurking variables are typically related to explanatory variables in the study. 3.A confounding variable is an explanatory variable that was considered in a study whose effect cannot be distinguished from a second explanatory variable in the study.
1---------statistics consists of organizing and summarizing information collected, while-2---------statistics uses methods that generalize results obtained from a sample to the population and measure the reliability of the results.
1.Descriptive 2.inferential
the ___1___ class limit is the smallest value within the class and the ____2__ class limit is the largest value within the class.
1.lower 2.upper
A polling organization contacts 2200 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. 1. What is the population in the study? 2. What is the sample in the study?
1.teenager that are 13 to 17 years old of age living in the united states 2.The 2200 teenagers who are 13 to 17 years of age and live in the United
Data were collected on 1,500 students' heights at a larger university on the east coast. Which of the following is the best chart for presenting the information?
A histogram
Fill in the blank below. _______ is a condition applied to the experimental units involved in an experiment.
A treatment
For the histogram on the right determine whether the mean is greater than, less than, or approximately equal to the median. Justify your answer.
A.x=M because the histogram is symmetric.
An instructor wishes to determine if there is a relationship between the number of absences from his class and a student's final grade in the course. What is the explanatory variable?
Absences
Which of the accompanying boxplots likely has the data with the larger standard deviation? Why?
Boxplot II likely has the data with the larger standard deviation because the boxplot appears to have a greater spread, which likely results in a larger standard deviation.
are the categories by which data are grouped.
Classes
To determine customer opinion of their safety features, Toyota randomly selects 140 dealerships during a certain week and surveys all customers visiting the dealerships. Question content area bottom Part 1 What type of sampling is used?
Cluster
Before premiering a blockbuster movie at a theater, test screenings are done beforehand. A small number of selected theaters are chosen geographically throughout the country. Each theater chosen is supposed to be representative of theatergoers in that area. Everyone is interviewed when the movie is over. Identify the type of sampling used in this example.
Cluster sampling
A internet site asks its members to call in their opinion regarding their web searching habits. Question content area bottom Part 1 What type of sampling is used?
Convenience
Identify which type of sampling is used: random, systematic, convenience, stratified, or cluster. A newspaper asks its readers to call in their opinion regarding the number of books they have read this month. Question content area bottom Part 1 Which type of sampling is used?
Convenience
number of aces held in a poker hand
Discrete, countable
Determine whether the given description corresponds to an observational study or an experiment. A doctor gives a new medication to half of his patients with the flu and a placebo to the other half of his patients with the flu.
Experiment
Determine whether the following statement is true or false. The shape of the distribution shown is best classified as skewed left. Question content area bottom Part 1 Choose the correct answer below.
False
The scatter diagram shows the relationship between average number of years of education and births per woman of child-bearing age in selected countries. Use the scatter plot to determine whether the statement is true or false.
False
True or False: A data set will always have exactly one mode.
False
A frequency table of grades has five classes (A, B, C, D, F) with frequencies of 3, 15, 17, 8, and 3 respectively. Using percentages, what are the relative frequencies of the five classes?
Grade Frequency Relative frequency A 3 6.526.52% B 15 32.6132.61% C 17 36.9636.96% D 8 17.3917.39% F 3 6.526.52%
What effect will an influential observation have upon the graph of the least squares regression line?
It will pull the graph toward the observation.
As part of a college literature course, students must select three classic works of literature from the provided list and complete critical book reviews for each selected work. Write a short description of the processes that can be used to generate a simple random sample of three books. Obtain a simple random sample of size 3 from this list.
List each book on a separate piece of paper, place them all in a hat, and pick three. Your answer is correct. Number the books from 1 to 9 and use a random number table to produce 3 different one digit numbers corresponding to the books selected.
Mr. Zuro finds the mean height of all 12 students in his statistics class to be 67.0 inches. Just as Mr. Zuro finishes explaining how to get the mean, Danielle walks in late. Danielle is 64.4 inches tall. What is the mean height of the 13 students in the class?
Mean height of the 13 students in the class = (67 * 12 + 64.4 * 1) / (12 + 1) = 66.8
Consider the information in the "Why we can't lose weight" chart shown to the right, which is in the magazine style of graph. Could the information provided be organized into a pie chart? Why or why not?
No. The percentages add up to more than 100%.
A newspaper article claimed that the afternoon hours were the worst in terms of robberies and provided the graph to the right in support of this claim. Explain how this graph is misleading.
Not all of the time intervals are the same size. Redistributing the time interval so they are all the same size may lead to a different shape.
A medical researcher wishes to determine if there is a relationship between the number of prescriptions written by pediatricians and the ages of the children for whom the prescriptions are written. She surveys all the pediatricians in a geographical region to collect her data. What is the response variable?
Number of prescriptions written
Identify the type of study that is used in this statement. A marketing firm does a survey to find out how many people use a product. Of the one hundred people contacted, fifteen said they use the product.
Observational study
What does it mean when sampling is done without replacement? Question content area bottom Part 1 Choose the correct answer below.
Once an individual is selected, the individual cannot be selected again.
are sample values that lie very far away from the majority of the other sample values.
Outliers
The chart available below is a poor representation of a categorical variable, which type of card people believe is safer to use. Why is this chart inappropriate?
Pictogram is used
_______ divide data sets in fourths.
Quartiles
wants to administer a satisfaction survey to its current customers. Using their customer database, the company randomly selects 80 customers and asks them about their level of satisfaction with the company. Question content area bottom Part 1 What type of sampling is used?
Simple random
the average 20 to 29 year old is 69.6 inches tall, with a standard deviation of 3.0 inches, while the average 20 to 29 year old woman is 64.1 inches tall, with a standard deviation of 3.8 inches. Who is relatively taller, a 75 inches man or a 70 inches woman?
Solution : Given that , mean = = 69.6 ( man ) standard deviation = = 3.0 x = 75 Using z-score formula, z = x - / z = 75 - 69.6 / 3.0 z = 1.80 ( man ) mean = = 64.1 ( woman ) standard deviation = = 3.8 x = 70 Using z-score formula, z = x - / z = 70 - 64.1 / 3.8 z = 1.55 ( woman ) Man z - score is 1.80 more than woman z-score 1.55 so, man is relatively taller than woman
Choose the correct answer below.
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.
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 Daimler−Chrysler selects every 12th van that comes off the assembly line starting with the eighth until she obtains a sample of 60 vans. Question content area bottom Part 1 Which type of sampling is used?
Systematic
A histogram of a set of data indicates that the distribution of the data is skewed right. Which measure of central tendency will likely be larger, the mean or the median? Why?
The mean will likely be larger because the extreme values in the right tail tend to pull the mean in the direction of the tail.
Explain why you believe the improved chart is better than the one included in the annual report. Select all the characterics of the improved chart that make it better than the old chart.
The new chart includes a title. The new chart labels both axes.
In sampling, explain why obtaining a representative sample is important. Why is obtaining a representative sample important?
The sample must be representative in order to use inferential statistics to draw conclusions about the entire population.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. It is impossible to have a z-score of 0.
The statement is false. A z-score of 0 is a standardized value that is equal to the mean.
Determine whether the following statement is true or false. If it is false, rewrite it as a true statement. The mean is the measure of central tendency most likely to be affected by an outlier.
The statement is true.
A student's score on an actuarial exam is in the 78th percentile. What can you conclude about the student's exam score?
The student scored higher than 78% of the students who took the actuarial exam.
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 science class
The study is an observational study because the study examines individuals in a sample,
a poll is conducted by a school's math department in which tenth-grade students are asked if they prefer to be in their math class or their english clas
The study is an observational study because the study examines individuals in a sample,
Determine whether the study depicts an observational study or an experiment. eighty patients with stomach cancer are divided into two groups. one group receivers an experimental drug to fight cancer, the other a placebo. after one year, the spread of the cancer is measure Does the description correspond to an observational study or an experiment?
The study is an experiment because the researchers control one variable to determine
Determine whether the underlined value is a parameter or a statistic. in championship football game, a quarterback complete 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
amount of fabric needed for a dress Is the variable qualitative or quantitative?
The variable is continuous because it is not countable.
number of touchdown thrown by quarterback Is the variable discrete or continuous?
The variable is discrete because it is countable.
street name of address Is the variable qualitative or quantitative?
The variable is qualitative because it is an attribute characteristic.
Determine whether the variable is qualitative or quantitative. rock group
The variable is qualitative because it is an attribute characteristic.
favorite musical style Is the variable qualitative or quantitative?
The variable is qualitative because it is an attribute characteristic.
A traffic officer is compiling information about the relationship between the hour of the day and the speed over the limit at which the motorist is ticketed. He computes a correlation coefficient of 0.12. What does this tell the officer?
There is a weak positive linear correlation.
The following data represents a random sample of 15 complaints registered with the customer service department of a store. Determine the median complaint.
There is no median complaint.
The chart available below is a poor representation of a numerical variable, the average consumer's Valentine's Day spending. Why is this chart inappropriate? Why is the chart inappropriate? Select all that apply.
There is no vertical axis. The chart does not need a legend. The background image and candy boxes are chartjunk. No units are listed.
Determine whether the following statement is true or false. Generally, the goal of an experiment is to determine the effect that the treatment will have on the response variable. Question content area bottom Part 1 Choose the correct answer below.
True
Determine whether the statement is true or false. Histograms are used for numerical data while bar charts are suitable for categorical data.
True
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. The second quartile is the median of an ordered data set.
True
_________ are the characteristics of the individuals of the population being studied.
Variables
A researcher determines that the linear correlation coefficient is 0.85 for a paired data set. This indicates that there is _______.
a strong positive linear correlation
The human resource department at a certain company wants to conduct a survey regarding worker benefits. The department has an alphabetical list of all 3408 employees at the company and wants to conduct a systematic sample of size 40. Question content area bottom Part 1 (a) What is k?
a)85 b)Determine the individuals who will be administered the survey. Randomly select a number from 1 to k. Suppose that we randomly select 14. Starting with the first individual selected, the individuals in the survey will be 1414, 9999, 184184..., 33293329.
The survey has bias. (a) Determine the type of bias. (b) Suggest a remedy. A polling organization conducts a study to estimate the percentage of households that place an emphasis on physical activity. It mails a questionnaire to 1694 randomly selected households across the country and asks the head of each household if he or she places an emphasis on physical activity. Of the 1694 households selected, 25 responded. Question content area bottom Part 1 (a) Which of these best describes the bias in the survey? (b) How can the bias be remedied?
a)Nonresponse bias b)The polling organization should try contacting households that do not respond by phone or face-to-face.
The following newspaper type graphic illustrates the ideal family size (total children) based on a survey of adults from a certain country. Complete parts (a) through (c) below. (a) What type of graphic is being displayed? (b) Describe any problems with the graphic. Select all that apply.
a.Bar graph b.-This data should have been displayed using a stem-and-leaf plot or an ogive instead of the current graphic. -It is difficult to determine which option that the people who don't know of an ideal family size responded.
The human resource group for a company collected data summarizing the educational level of the company's employees. They found that 160 have no college degree (None), 40 have an associate's degree (AA), 227 have a bachelor's degree (BA), 46 have a master's degree (MA), and 33 have PhDs. Complete parts a and b below. Question content area bottom Part 1 a) Make a frequency table for the education level of the company. b) Make a relative frequency table for the education level of the company.
a.Level Frequency None 160 AA 40 BA 227 MA 46 PhD 33 b.Level Relative Frequency None 31.62% AA 7.91% BA 44.86% MA 9.09% PhD 6.52%
The survey has bias. (a) Determine the type of bias. (b) Suggest a remedy. Suppose you are conducting a survey regarding violence in hockey in a youth hockey league. You obtain a cluster sample of 16 hockey teams within a youth hockey league and sample all hockey players in the randomly selected hockey teams. The survey is administered by the coaches. Question content area bottom Part 1 (a) Which of these best describes the bias in the survey? (b) How can the bias be remedied?
a.Response bias b.The survey should be administered by an impartial party.
The following survey has bias. (a) Determine the type of bias. (b) Suggest a remedy. A retail store manager wants to conduct a study regarding the shopping habits of his customers. He selects the first 60 customers who enter his store on a Saturday morning. Question content area bottom Part 1 (a) What is the type of bias? (b) What is a possible remedy?
a.Sampling bias b.use systematic random sampling
a) How is the graph misleading? (b) What could be done to improve the graphic?
a.looks twicE as much money b.the lenght of the bar
The pie chart shows the percentage of votes received by each candidate in the student council presidential election. Gina 22% Ann 17% Ted 35% Ming 26% 200 total votes Student Council President Who got the fewest votes?
ann
b. Does there appear to be any change in real annual sales over time? Explain.
b.Although sales both started and ended this time period at the same amount, they were
b. What pattern, if any, is present in the data?
b.Home prices appear to be increasing from 2000 to 2006 and decreasing from 2006 to 2010.
The _________________ is the difference between consecutive lower class limits.
class width
Fill in the blank below. When the effects of the explanatory variable upon the response variable cannot be determined, then _______.
confounding has occurred
Determine whether the study depicts an observational study or an experiment. A medical researcher obtains a sample of adults suffering from diabetes. She randomly assigns 31 people to a treatment group and 31 to a placebo group. The treatment group receives a medication over a period of three months and the placebo group receives a placebo over the same time frame. At the end of three months the patients' symptoms are evaluated.
experiment
The following data represent the living situation of newlyweds in a large metropolitan area and their annual household income. Find the marginal frequency for newlyweds who live with family. <$20,000 $20−35,000 $35−50,000 $50−75,000 >$75,000 Own home3152202355524Rent home6766522311Live w/family89693042
https://www.chegg.com/homework-help/questions-and-answers/following-data-represent-living-situation-newlyweds-large-metropolitan-area-annual-househo-q10968879?trackid=5caa12d39dc5&strackid=edd0c7e3ecba
n one area of Russia, records were kept on the relationship between the rainfall (in inches) and the yield of wheat (bushels per acre). The data for a 9 year period is as shown below. Rainfall, x 13.1 11.4 16.0 15.1 21.4 12.9 9.6 18.2 18.6Yield, y 48.5 44.2 56.8 80.4 47.2 29.9 74.0 74.0 76.8 The equation of the line of least squares is given as y=−9.12+4.38x. How many bushels of wheat per acre can be predicted if it is expected that there will be 17 inches of rain?
https://www.chegg.com/homework-help/questions-and-answers/one-area-russia-records-kept-relationship-rainfall-inches-yield-wheat-bushels-per-acre--da-q48593120?trackid=21a14d134c0a&strackid=71894634ecbc
A pediatrician wants to determine the relation that may exist between a child's height and head circumference. She randomly selects eleven 3-year-old children from her practice and measures their heights and head circumference. According to the data, the linear correlation coefficient between the height and head circumference of a child is 0.918. Compute the coefficient of determination, R2.
https://www.chegg.com/homework-help/questions-and-answers/pis-possible-pediatrician-wants-determine-relation-may-exist-child-s-height-head-circumfer-q56119611?trackid=09d60f308dbe&strackid=1e962bb7cbea
A(n) _________ is a person or object that is a member of the population being studied.
individual
Which measure of central tendency best describes the weight of the candy?
median
Determine whether the study depicts an observational study or an experiment. A poll is conducted in which professional musicians are asked their ages.
observational study
An Excel printout of some descriptive statistics for a set of data is shown to the right. What is the IQR?
page 16
Calculate the linear correlation coefficient for the data below. Round to three decimal places.
page 16
Find the equation of the regression line for the given data. Round values to the nearest thousandth.
page 17
Following the central limit theorem, what is the Z score for random variable X that equals 10, given the mean of the population is 5 and the standard deviation is 20, and the sample size of 25.
page 5 on paper
The data represent the age of world leaders on their day of inauguration. Find the five-number summary, and construct a boxplot for the data. Comment on the shape of the distribution. 48 58 48 68 49 56 62 50 65 55 57 43 64 57 43 Question content area bottom Part 1 The five-number summary is
page 5 on paper
is a numerical summary of a population.
parameter
Use the portion of the random number table provided below to obtain a simple random sample of size 3 from this list. If you start on the left and take the first three numbers between 1 and 9, what three books would be selected from the numbered list? 75570 95526 8930
pride and prejudice, huckleberry finn, the jungle
A Highly selective boarding school will only admit students who have 2 standard deviations above the mean on a standardized test that has a mean of 300 and a standard deviation of 24. what is the minnimum score that an applicant must make on the test to be accepted ?
standard deviation+24. mean+300. 2 standard deviation+2*24=48. minimum score =300+48=348
is a numerical summary of a sample.
statistic
A drug company wanted to test a new acne medication. The researchers found 300 adults aged 25-35 and randomly assigned them to two groups. The first group received the new drug, while the second received a placebo. After one month of treatment, the percentage of each group whose acne symptoms decreased was recorded and compared. Identify the experimental units.
the 300 adults aged 25-35
A farmer wishes to test the effects of a new fertilizer on her soybean yield. She has four equal-sized plots of land. One plot has sandy soil, one has rocky soil, one has clay-rich soil, and one has average soil. She divides each of the four plots into three equal-sized portions and randomly labels them A, B, and C. The four A portions of land are treated with her old fertilizer, the four B portions of land are treated with the new fertilizer, and the four C portions of land are treated with no fertilizer. At harvest time, the soybean yield is recorded for each section of land. What is the treatment in this experiment?
the fertilizers
Fill in the blank below. The variable measured in an experiment is called _______.
the response variable
Determine whether the variable is qualitative or quantitative. favorite musical band Is the variable qualitative or quantitative?
the variable is qualitative because it is an attribute characteristic.
The graphs available below represent the average per kilowatt-hour prices of electricity in a certain country for the years 2003 to 2010. Which graph does a good job revealing what the data convey and which graph is a poorly constructed graphical display? Explain. does a good job revealing what the data convey. The other graph is a poorly constructed graphical display because
the vertical axis does not begin at zero.
The accompanying bar graph shows the number of tickets sold each week by the garden club for their annual flower show. During which week was the most number of tickets sold?
week 4
The _______ represents the number of standard deviations an observation is from the mean.
z-score
The accomapnying bar graph shows the political party affiliation of 1000 registered voters in a certain country. What percentage of the 1000 registered voters belonged to one of the traditional two parties (Democratic and Republican)?
75%
Determine whether the following statement is true or false. Explain. Inferences based on voluntary response samples are generally not reliable.
True, because it is often the case that the individuals who volunteer do not accurately represent the population.
Fill in the blank below. An experiment in which neither the experimental unit nor the researcher in contact with the experimental unit knows which treatment the experimental unit is receiving is called a _______.
double-blind experiment
Given the following least squares prediction equation, y=−173+74x, y is estimated to _______ by _______ with each 1-unit increase in x.
increase; 74 units
