Question 1

The relative risk of a disease for group 1 compared to group 2 is close to the odds ratio under which of these circumstances?

Accepted Answer

A)  When the numbers with the disease in each group are small compared to the total in each group. 
B)  When the numbers with the disease are about equal to the numbers without the disease in each group. 
C)  When the numbers with the disease in each group are almost equal to the total in each group. 
D)  The relative risk and the odds ratio are never close to each other. 
A)  When the numbers with the disease in each group are small compared to the total in each group. 
B)  When the numbers with the disease are about equal to the numbers without the disease in each group. 
C)  When the numbers with the disease in each group are almost equal to the total in each group. 
D)  The relative risk and the odds ratio are never close to each other.

Question 2

Explain in your own words or through an example what Simpson's paradox is.

Accepted Answer

Simpson's paradox occurs when

Question 3

Pick the choice that best completes the following sentence. If a relationship between two variables is called statistically significant, it means the investigators think the variables are

Accepted Answer

A)  related in the population represented by the sample. 
B)  not related in the population represented by the sample. 
C)  related in the sample due to chance alone. 
D)  very important. 
A)  related in the population represented by the sample. 
B)  not related in the population represented by the sample. 
C)  related in the sample due to chance alone. 
D)  very important.

Question 4

A study on the use of seat belts versus belted booster seats for children ages 4 and 5 reported that "Using seat belts instead of booster seats was associated with increased risk for serious injury in an accident; the relative risk was 2.4."Based on this, it can be concluded that for this study:

Accepted Answer

A)  Children ages 4 and 5 in a booster seat were 2.4 times more likely to have serious injuries in an accident than were children wearing seatbelts. 
B)  Children ages 4 and 5 wearing seatbelts were 2.4 times more likely to have serious injuries in an accident than were children in a booster seat. 
C)  The percent of children ages 4 and 5 in a booster seat was 2.4 times higher than the percent of children wearing seatbelts. 
D)  The percent of children ages 4 and 5 wearing seatbelts was 2.4 times higher than the percent of children in a booster seat. 
A)  Children ages 4 and 5 in a booster seat were 2.4 times more likely to have serious injuries in an accident than were children wearing seatbelts. 
B)  Children ages 4 and 5 wearing seatbelts were 2.4 times more likely to have serious injuries in an accident than were children in a booster seat. 
C)  The percent of children ages 4 and 5 in a booster seat was 2.4 times higher than the percent of children wearing seatbelts. 
D)  The percent of children ages 4 and 5 wearing seatbelts was 2.4 times higher than the percent of children in a booster seat.

Question 5

The statistical significance of the association or relationship between two categorical variables is examined using a value known as the chi-square statistic, and a corresponding p-value that assesses the chance of getting this value for the Chi-square statistic or one even larger. Suppose the p-value of the test turns out to be 0.18. In this case, we should decide that

Accepted Answer

A)  there is only an 18% chance that the observed relationship occurred by chance, so we can say that the relationship is statistically significant. 
B)  the observed relationship most likely did not occur by chance, so we can say that the relationship is statistically significant. 
C)  the observed relationship most likely did not occur by chance, so we cannot say that the relationship is statistically significant. 
D)  the observed relationship could have occurred by chance, so we cannot say that the relationship is statistically significant 
A)  there is only an 18% chance that the observed relationship occurred by chance, so we can say that the relationship is statistically significant. 
B)  the observed relationship most likely did not occur by chance, so we can say that the relationship is statistically significant. 
C)  the observed relationship most likely did not occur by chance, so we cannot say that the relationship is statistically significant. 
D)  the observed relationship could have occurred by chance, so we cannot say that the relationship is statistically significant

Question 6

Use the following information for questions:
The table shows the opinions of 1027 respondents in the General Social Survey to the question "Is there any area right around here - that is, within a mile - where you would be afraid to walk alone at night?" The purpose of examining the data is to see if there is a gender difference in how people would respond to this question.  
-State the null and alternative hypotheses for this study.

Accepted Answer

Null hypothesis: There is no relationshi

Question 7

Use the following information for questions:
Students in a statistics class were asked, "With whom do you find it easier to make friends: person of the same sex, person of opposite sex, or no preference?" A table summarizing the responses by gender is given below. Minitab results for a chi-square test for these data were "Chi-Sq = 7.15 DF=2 P-value = 0.028."  
-Among females, what percent said "same sex?"

Accepted Answer

A)  15% 
B)  25% 
C)  30% 
D)  60% 
A)  15% 
B)  25% 
C)  30% 
D)  60%

Question 8

Use the following information for questions:
 The table below summarizes, by gender of respondent, the responses from 1,033 people to the question, "Do you smoke?"  
-What is the odds ratio for women smoking (to not smoking) compared to men?

Accepted Answer

A)  0.87 
B)  0.91 
C)  1.10 
D)  1.15 
A)  0.87 
B)  0.91 
C)  1.10 
D)  1.15

Question 9

The relative risk of allergies for children of parents who smoke compared to children of parents who don't smoke is 3.0. Suppose that the risk of allergies for the children of non-smokers is 0.15 (15%). What is the risk of allergies for the children of smokers?

Accepted Answer

A)  3% 
B)  5% 
C)  30% 
D)  45% 
A)  3% 
B)  5% 
C)  30% 
D)  45%

Question 10

A 1995 Washington Post-ABC News Poll on Affirmative Action reported that 76 percent of men and 69 percent of women opposed giving preferences to women in hiring, promotions and college admissions. What are the odds that a woman was opposed to giving preferences versus not opposed?

Accepted Answer

The odds of being op

Question 11

Use the following information for questions:
 The table below shows the opinions of 321 respondents from the General Social Survey by whether they owned a gun (or not) and whether they favored (or opposed) a law requiring a permit to own a gun.  
-Based on the chi-square statistic and p-value, one can conclude that

Accepted Answer

A)  the difference between the support for the gun law between gun owners and non-gun owners is not statistically significant. 
B)  the difference between the support for the gun law between gun owners and non-gun owners is statistically significant. 
C)  the difference between the support for the gun law between gun owners and non-gun owners is not practically significant. 
D)  the difference between the support for the gun law between gun owners and non-gun owners is practically significant. 
A)  the difference between the support for the gun law between gun owners and non-gun owners is not statistically significant. 
B)  the difference between the support for the gun law between gun owners and non-gun owners is statistically significant. 
C)  the difference between the support for the gun law between gun owners and non-gun owners is not practically significant. 
D)  the difference between the support for the gun law between gun owners and non-gun owners is practically significant.

Question 12

A statistically significant relationship between two categorical variables is illustrated in the sample as one that

Accepted Answer

A)  is small enough that it is likely to have occurred in the observed sample even if there is no relationship in the population. 
B)  is small enough that it is unlikely to have occurred in the observed sample if there is no relationship in the population. 
C)  is large enough that it is likely to have occurred in the observed sample even if there is no relationship in the population 
D)  is large enough that it is unlikely to have occurred in the observed sample if there is no relationship in the population 
A)  is small enough that it is likely to have occurred in the observed sample even if there is no relationship in the population. 
B)  is small enough that it is unlikely to have occurred in the observed sample if there is no relationship in the population. 
C)  is large enough that it is likely to have occurred in the observed sample even if there is no relationship in the population 
D)  is large enough that it is unlikely to have occurred in the observed sample if there is no relationship in the population

Question 13

Use the following information for questions:
 A researcher conducted a study on college students to see if there was a link between gender and how often they have cheated on an exam. She asked two questions on a survey:
(1) What is your gender? Male ___ Female ___
(2) How many times have you cheated on an exam while in college?
Never __ 1 or 2 times ___ 3 or more times ___
A two-way table of observed counts follows:
  
-What percent of the students in the study cheated 3 or more times on an exam?

Accepted Answer

A)  20% 
B)  10% 
C)  30% 
D)  15% 
A)  20% 
B)  10% 
C)  30% 
D)  15%

Question 14

What is the primary purpose of doing a chi-square test?

Accepted Answer

A)  to determine if there is a significant relationship between two quantitative variables 
B)  to determine if there is a significant relationship between two categorical variables 
C)  to determine if there is a significant relationship between two continuous variables 
D)  to estimate a population proportion 
A)  to determine if there is a significant relationship between two quantitative variables 
B)  to determine if there is a significant relationship between two categorical variables 
C)  to determine if there is a significant relationship between two continuous variables 
D)  to estimate a population proportion

Question 15

Use the following information for questions:
The table below shows the ratings given by 200 students in an introductory statistics course. There were two instructors for the course, each with 100 students.   
-What percent of Jones' students rated the teaching as high quality?

Accepted Answer

A)  38% 
B)  62% 
C)  50% 
A)  38% 
B)  62% 
C)  50%

Question 16

Use the following information for questions:
 The table below shows the counts by gender and highest degree attained for 498 respondents in the General Social Survey.
  
-What percent of the sample were males?

Accepted Answer

A)  43.6% 
B)  48.5% 
C)  56.4% 
D)  77.2% 
A)  43.6% 
B)  48.5% 
C)  56.4% 
D)  77.2%

Question 17

A study done by the Center for Academic Integrity at Rutgers University surveyed 2116 students at 21 colleges and universities. Some of the schools had an "honor code"and others did not. Of the students at schools with an honor code, 7% reported having plagiarized a paper via the Internet, while at schools with no honor code, 13% did so. (Sacramento Bee, Feb 29, 2000, D1.) Although the data provided are not sufficient to carry out a chi-square test of the relationship between whether or not a school has an honor code and whether or not a student would plagiarize a paper via the Internet, suppose such a test were to show a statistically significant relationship on the basis of this study. What would be the correct conclusion?

Accepted Answer

A)  Because this is an observational study, it can be concluded that implementing an honor code at a college or university will reduce the risk of plagiarism. 
B)  Because this is a randomized experiment, it can be concluded that implementing an honor code at a college or university will reduce the risk of plagiarism. 
C)  Because this is an observational study and confounding variables are likely, it cannot be concluded that implementing an honor code at a college or university will reduce the risk of plagiarism. 
D)  Because this is a randomized experiment and confounding variables are likely, it cannot be concluded that implementing an honor code at a college or university will reduce the risk of plagiarism. 
A)  Because this is an observational study, it can be concluded that implementing an honor code at a college or university will reduce the risk of plagiarism. 
B)  Because this is a randomized experiment, it can be concluded that implementing an honor code at a college or university will reduce the risk of plagiarism. 
C)  Because this is an observational study and confounding variables are likely, it cannot be concluded that implementing an honor code at a college or university will reduce the risk of plagiarism. 
D)  Because this is a randomized experiment and confounding variables are likely, it cannot be concluded that implementing an honor code at a college or university will reduce the risk of plagiarism.

Question 18

Use the following information for questions:
The table below shows the opinions of 908 respondents in the General Social Survey to the question "Do you believe there is life after death?"  
-What percent of males believe in life after death?

Accepted Answer

The answer of Use the following information for questions:
The table...

Question 19

Use the following information for questions:
 The table below shows the responses from a sample of 680 people in the General Social Survey to the question, "Do you sometimes drink more than you think you should?"  
-What is the odds ratio for women thinking they drank more than they should compared to men?

Accepted Answer

A)  0.41 
B)  0.57 
C)  1.76 
D)  2.41 
A)  0.41 
B)  0.57 
C)  1.76 
D)  2.41

Question 20

Use the following information for questions:
In a survey of 1000 adults, respondents were asked about the expense of a college education and the relative necessity of financial assistance. The correspondents were classified as to whether they currently had a child in college or not (college status), and whether they thought the loan obligation for most college students was too high, about right, or too little (loan obligation opinion). The table below summarizes some of the survey results. Use these results to answer the following questions.
  
-The table below shows the row percentages   Based on these percentages, describe the relationship between loan obligation opinion and college status.

Accepted Answer

There does appear to be some association

The relative risk of a disease for group 1 compared to group 2 is close to the odds ratio under which of these circumstances?

Explain in your own words or through an example what Simpson's paradox is.

Pick the choice that best completes the following sentence. If a relationship between two variables is called statistically significant, it means the investigators think the variables are

A study on the use of seat belts versus belted booster seats for children ages 4 and 5 reported that "Using seat belts instead of booster seats was associated with increased risk for serious injury in an accident; the relative risk was 2.4."Based on this, it can be concluded that for this study:

Use the following information for questions: The table below summarizes, by gender of respondent, the responses from 1,033 people to the question, "Do you smoke?" -What is the odds ratio for women smoking (to not smoking) compared to men?

The relative risk of allergies for children of parents who smoke compared to children of parents who don't smoke is 3.0. Suppose that the risk of allergies for the children of non-smokers is 0.15 (15%). What is the risk of allergies for the children of smokers?

A 1995 Washington Post-ABC News Poll on Affirmative Action reported that 76 percent of men and 69 percent of women opposed giving preferences to women in hiring, promotions and college admissions. What are the odds that a woman was opposed to giving preferences versus not opposed?

A statistically significant relationship between two categorical variables is illustrated in the sample as one that

What is the primary purpose of doing a chi-square test?

Use the following information for questions: The table below shows the ratings given by 200 students in an introductory statistics course. There were two instructors for the course, each with 100 students. -What percent of Jones' students rated the teaching as high quality?

Use the following information for questions: The table below shows the counts by gender and highest degree attained for 498 respondents in the General Social Survey. -What percent of the sample were males?

Use the following information for questions: The table below shows the opinions of 908 respondents in the General Social Survey to the question "Do you believe there is life after death?" -What percent of males believe in life after death?

Statistics Success Stories and Cautionary Tales

Turning Data Into Information

Relationships Between Quantitative Variables

Sampling: Surveys and How to Ask Questions

Gathering Useful Data for Examining Relationships

Probability

Random Variables

Understanding Sampling Distributions: Statistics As Random Variables

Estimating Proportions With Confidence

Estimating Means With Confidence

Testing Hypotheses About Proportions

Testing Hypotheses About Means

Inference About Simple Regression

More About Inference for Categorical Variables

Analysis of Variance

Turning Information Into Wisdom

Filters

Exam 4: Relationships Between Categorical Variables

The relative risk of a disease for group 1 compared to group 2 is close to the odds ratio under which of these circumstances?

Explain in your own words or through an example what Simpson's paradox is.

Pick the choice that best completes the following sentence. If a relationship between two variables is called statistically significant, it means the investigators think the variables are

A study on the use of seat belts versus belted booster seats for children ages 4 and 5 reported that "Using seat belts instead of booster seats was associated with increased risk for serious injury in an accident; the relative risk was 2.4."Based on this, it can be concluded that for this study:

Use the following information for questions: The table below summarizes, by gender of respondent, the responses from 1,033 people to the question, "Do you smoke?" -What is the odds ratio for women smoking (to not smoking) compared to men?

The relative risk of allergies for children of parents who smoke compared to children of parents who don't smoke is 3.0. Suppose that the risk of allergies for the children of non-smokers is 0.15 (15%). What is the risk of allergies for the children of smokers?

A 1995 Washington Post-ABC News Poll on Affirmative Action reported that 76 percent of men and 69 percent of women opposed giving preferences to women in hiring, promotions and college admissions. What are the odds that a woman was opposed to giving preferences versus not opposed?

A statistically significant relationship between two categorical variables is illustrated in the sample as one that

What is the primary purpose of doing a chi-square test?

Use the following information for questions: The table below shows the ratings given by 200 students in an introductory statistics course. There were two instructors for the course, each with 100 students. -What percent of Jones' students rated the teaching as high quality?

Use the following information for questions: The table below shows the counts by gender and highest degree attained for 498 respondents in the General Social Survey. -What percent of the sample were males?

Use the following information for questions: The table below shows the opinions of 908 respondents in the General Social Survey to the question "Do you believe there is life after death?" -What percent of males believe in life after death?

Statistics Success Stories and Cautionary Tales

Turning Data Into Information

Relationships Between Quantitative Variables

Sampling: Surveys and How to Ask Questions

Gathering Useful Data for Examining Relationships

Probability

Random Variables

Understanding Sampling Distributions: Statistics As Random Variables

Estimating Proportions With Confidence

Estimating Means With Confidence

Testing Hypotheses About Proportions

Testing Hypotheses About Means

Inference About Simple Regression

More About Inference for Categorical Variables

Analysis of Variance

Turning Information Into Wisdom

Filters