1. Active Learning Lecture Slides For use with Classroom Response Systems
Association: Contingency, Correlation, and Regression

2. 3.1 Below is a contingency table of the results of two
questions asked during the 2006 GSS. Participants
were asked if gun control should be stricter after the
9/11/01 tragedy and about their political party
affiliation. Find the conditional proportion of
Republicans that think that gun control laws should be
stricter.
Should be stricter
Should be less strict
Total
Democrat
454 62
516
Independent
195 37
232
Republican
363
104
467
1012
203
1215
a) 363 / 1215
b) 363 / 1012
c) 363 / 467
d) 1012 / 1215
e) 467 / 1215
Copyright © 2013 Pearson Education, Inc.

3. 3.1 Below is a contingency table of the results of two
questions asked during the 2006 GSS. Participants
were asked if gun control should be stricter after the
9/11/01 tragedy and about their political party
affiliation. Find the conditional proportion of
Republicans that think that gun control laws should be
stricter.
Should be stricter
Should be less strict
Total
Democrat
454 62
516
Independent
195 37
232
Republican
363
104
467
1012
203
1215
a) 363 / 1215
b) 363 / 1012
c) 363 / 467
d) 1012 / 1215
e) 467 / 1215
Copyright © 2013 Pearson Education, Inc.

4. 3.2 Below is a contingency table of the results of two
questions asked during the 2006 GSS. Participants
were asked if gun control should be stricter after the
9/11/01 tragedy and about their political party
affiliation. Find the conditional proportion of Democrats
think that gun control laws should be stricter.
Should be stricter
Should be less strict
Total
Democrat
454 62
516
Independent
195 37
232
Republican
363
104
467
1012
203
1215
a) 454 / 516
b) 454 / 1012
c) 454 / 1215
d) 1012 / 1215
e) 516 / 1215
Copyright © 2013 Pearson Education, Inc.

5. 3.2 Below is a contingency table of the results of two
questions asked during the 2006 GSS. Participants
were asked if gun control should be stricter after the
9/11/01 tragedy and about their political party
affiliation. Find the conditional proportion of Democrats
think that gun control laws should be stricter.
Should be stricter
Should be less strict
Total
Democrat
454 62
516
Independent
195 37
232
Republican
363
104
467
1012
203
1215
a) 454 / 516
b) 454 / 1012
c) 454 / 1215
d) 1012 / 1215
e) 516 / 1215
Copyright © 2013 Pearson Education, Inc.

6. 3.3 Below is a contingency table of the results of two
questions asked during the 2006 GSS. Participants
were asked if gun control should be stricter after the
9/11/01 tragedy and about their political party
affiliation. What percentage of those surveyed think
that gun control laws should be stricter?
Should be stricter
Should be less strict
Total
Democrat
454 62
516
Independent
195 37
232
Republican
363
104
467
1012
203
1215
a) 77%
b) 83%
c) 84%
d) 88%
e) 90%
Copyright © 2013 Pearson Education, Inc.

7. 3.3 Below is a contingency table of the results of two
questions asked during the 2006 GSS. Participants
were asked if gun control should be stricter after the
9/11/01 tragedy and about their political party
affiliation. What percentage of those surveyed think
that gun control laws should be stricter?
Should be stricter
Should be less strict
Total
Democrat
454 62
516
Independent
195 37
232
Republican
363
104
467
1012
203
1215
a) 77%
b) 83%
c) 84%
d) 88%
e) 90%
Copyright © 2013 Pearson Education, Inc.

8. 3.4 A personal trainer decides to track the
amount of time each of her clients spends
exercising and their amount of weight loss in a two
month period. What are the explanatory and
response variables?
a) Explanatory variable: time spent exercising
Response variable: weight loss
b) Explanatory variable: weight loss
Response variable: time spent exercising
c) Cannot be determined
Copyright © 2013 Pearson Education, Inc.

9. 3.4 A personal trainer decides to track the
amount of time each of her clients spends
exercising and their amount of weight loss in a two
month period. What are the explanatory and
response variables?
a) Explanatory variable: time spent exercising
Response variable: weight loss
b) Explanatory variable: weight loss
Response variable: time spent exercising
c) Cannot be determined
Copyright © 2013 Pearson Education, Inc.

10. 3.5 A psychologist believes that people who have a
religious belief system are happier. She asks 10
people each of the Jewish, Christian, Islamic, Hindu
and Buddhist religions as well as 10 people who claim
no religion to rate their happiness on a 5 point scale.
Which more naturally is the response variable and the
explanatory variable?
a) Explanatory variable: happiness rating
Response variable: religion
b) Explanatory variable: religion
Response variable: happiness rating
c) Cannot be determined
Copyright © 2013 Pearson Education, Inc.

11. 3.5 A psychologist believes that people who have a
religious belief system are happier. She asks 10
people each of the Jewish, Christian, Islamic, Hindu
and Buddhist religions as well as 10 people who claim
no religion to rate their happiness on a 5 point scale.
Which more naturally is the response variable and the
explanatory variable?
a) Explanatory variable: happiness rating
Response variable: religion
b) Explanatory variable: religion
Response variable: happiness rating
c) Cannot be determined
Copyright © 2013 Pearson Education, Inc.

12. 3.6 What type of graphic would you use to
explore the association between two quantitative
variables?
a) Contingency Table
b) Side-by-Side Boxplots
c) Scatterplots
d) All of the above
Copyright © 2013 Pearson Education, Inc.

13. 3.6 What type of graphic would you use to
explore the association between two quantitative
variables?
a) Contingency Table
b) Side-by-Side Boxplots
c) Scatterplots
d) All of the above
Copyright © 2013 Pearson Education, Inc.

14. 3.7 The scatterplot below shows a graph of median
family incomes per state as determined by the US
Census for 1969 versus In general, what can be
said about the straight line association between the
variables?
a) Strong, negative
b) Strong, positive
c) Weak, negative
d) Weak, positive
Copyright © 2013 Pearson Education, Inc.

15. 3.7 The scatterplot below shows a graph of median
family incomes per state as determined by the US
Census for 1969 versus In general, what can be
said about the straight line association between the
variables?
a) Strong, negative
b) Strong, positive
c) Weak, negative
d) Weak, positive
Copyright © 2013 Pearson Education, Inc.

16. 3.8 Which of the following properties is NOT a
property of correlation (r)?
a) It is unitless.
b) It ranges from –1 to 1.
c) It measures the strength of any type of
relationship between x and y.
d) If r = 0.9, the data exhibits a positive linear relationship.
e) It is not resistant to outliers.
Copyright © 2013 Pearson Education, Inc.

17. 3.8 Which of the following properties is NOT a
property of correlation (r)?
a) It is unitless.
b) It ranges from –1 to 1.
c) It measures the strength of any type of
relationship between x and y.
d) If r = 0.9, the data exhibits a positive linear relationship.
e) It is not resistant to outliers.
Copyright © 2013 Pearson Education, Inc.

18. 3.9 What value of “r” below best describes the scatterplot below?
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19. 3.9 What value of “r” below best describes the scatterplot below?
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20. 3.10 What value of “r” below would you expect if
you were comparing the number of hours that
students spend studying versus their GPA? a) b) c) d)
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21. 3.10 What value of “r” below would you expect if
you were comparing the number of hours that
students spend studying versus their GPA? a) b) c) d)
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22. 3.11 A least squares regression equation was
created from last year’s students data to predict
Exam 3 scores based on Exam 1 scores. The
equation was:
Predict the score on Exam 3 for a student that scored an 80 on Exam 1.
a) 69.70
b) 79.89
c) 85.53
d) 89.33
e) 90.53
Copyright © 2013 Pearson Education, Inc.

23. 3.11 A least squares regression equation was
created from last year’s students data to predict
Exam 3 scores based on Exam 1 scores. The
equation was:
Predict the score on Exam 3 for a student that scored an 80 on Exam 1.
a) 69.70
b) 79.89
c) 85.53
d) 89.33
e) 90.53
Copyright © 2013 Pearson Education, Inc.

24. 3.12 In northern cities roads are salted to keep ice from freezing
on the roadways between 0 and -9.5° C. Suppose that a small
city was trying to determine what was the average amount of salt
(in tons) needed per night at certain temperatures. They found
the following LSR equation:
Interpret the y-intercept.
2,500 tons is the average decrease in the amount of salt needed for a 1 degree increase in temperature.
b) Do not interpret. There is no data around x= 0° C.
c) 20,000 tons is the predicted amount of salt needed when the temperature is 0° C.
d) 2,500 tons is the predicted amount of salt needed when the temperatures is 0° C.
Copyright © 2013 Pearson Education, Inc.

25. 3.12 In northern cities roads are salted to keep ice from freezing
on the roadways between 0 and -9.5° C. Suppose that a small
city was trying to determine what was the average amount of salt
(in tons) needed per night at certain temperatures. They found
the following LSR equation:
Interpret the y-intercept.
2,500 tons is the average decrease in the amount of salt needed for a 1 degree increase in temperature.
b) Do not interpret. There is no data around x= 0° C.
c) 20,000 tons is the predicted amount of salt needed when the temperature is 0° C.
d) 2,500 tons is the predicted amount of salt needed when the temperatures is 0° C.
Copyright © 2013 Pearson Education, Inc.

26. 3.13 In northern cities roads are salted to keep ice from
freezing on the roadways between 0 and -9.5° C. Suppose
that a small city was trying to determine what was the
average amount of salt (in tons) needed per night at certain
temperatures. They found the following LSR equation:
Interpret the slope.
a) 2,500 tons is the average decrease in the amount of salt
needed for a 1 degree increase in temperature.
b) 2,500 tons is the average increase in the amount of salt
c) 20,000 is the average increase in the amount of salt needed
for a 1 degree increase in temperature.
Copyright © 2013 Pearson Education, Inc.

27. 3.13 In northern cities roads are salted to keep ice from
freezing on the roadways between 0 and -9.5° C. Suppose
that a small city was trying to determine what was the
average amount of salt (in tons) needed per night at certain
temperatures. They found the following LSR equation:
Interpret the slope.
a) 2,500 tons is the average decrease in the amount of salt
needed for a 1 degree increase in temperature.
b) 2,500 tons is the average increase in the amount of salt
c) 20,000 is the average increase in the amount of salt needed
for a 1 degree increase in temperature.
Copyright © 2013 Pearson Education, Inc.

28. 3.14 From 1974 to 1990 the GSS asked how happy people were in their marriage. The percentage of people that said “very happy” was plotted over time. Use the summary statistics below to compute the least squares regression line to predict the percent of those that are “very happy” in their marriage based on the year. a) b) c) d)
Copyright © 2013 Pearson Education, Inc.

29. 3.14 From 1974 to 1990 the GSS asked how happy people were in their marriage. The percentage of people that said “very happy” was plotted over time. Use the summary statistics below to compute the least squares regression line to predict the percent of those that are “very happy” in their marriage based on the year. a) b) c) d)
Copyright © 2013 Pearson Education, Inc.

30. e) Cannot be determined
3.15 A least squares regression equation was created from last year’s students data to predict Exam 3 scores based on Exam 1 scores. The equation was:
Suppose that a student made a 60 on Exam 1 and an 80 on Exam 3. Find the residual.
a) 0.36
b) 0.54
c) -0.36
d) -0.54
e) Cannot be determined
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31. e) Cannot be determined
3.15 A least squares regression equation was created from last year’s students data to predict Exam 3 scores based on Exam 1 scores. The equation was:
Suppose that a student made a 60 on Exam 1 and an 80 on Exam 3. Find the residual.
a) 0.36
b) 0.54
c) -0.36
d) -0.54
e) Cannot be determined
Copyright © 2013 Pearson Education, Inc.

32. 3.16 An experimenter wants to determine if a
particular type of diet cat food (brand A or B) tends to
have the most weight loss for Abyssinian and
Siamese cats. In order to make the experiment
easier to run he gives brand A to only Abyssinian
cats and brand B to only Siamese cats. What type of
error has been made?
a) Simpson’s Paradox
b) Interpolation
c) Extrapolation
d) Confounding
e) No error has been made
Copyright © 2013 Pearson Education, Inc.

33. 3.16 An experimenter wants to determine if a
particular type of diet cat food (brand A or B) tends to
have the most weight loss for Abyssinian and
Siamese cats. In order to make the experiment
easier to run he gives brand A to only Abyssinian
cats and brand B to only Siamese cats. What type of
error has been made?
a) Simpson’s Paradox
b) Interpolation
c) Extrapolation
d) Confounding
e) No error has been made
Copyright © 2013 Pearson Education, Inc.

34. e) No error has been made
3.17 The GSS survey asked married men from 1974 to 2006 how happy they were in their marriage. According to this formula, in 2050 only 51.5% of married men will be very happy. What type of error has been made here?
a) Simpson’s Paradox
b) Interpolation
c) Extrapolation
d) Confounding
e) No error has been made
Copyright © 2013 Pearson Education, Inc.

35. e) No error has been made
3.17 The GSS survey asked married men from 1974 to 2006 how happy they were in their marriage. According to this formula, in 2050 only 51.5% of married men will be very happy. What type of error has been made here?
a) Simpson’s Paradox
b) Interpolation
c) Extrapolation
d) Confounding
e) No error has been made
Copyright © 2013 Pearson Education, Inc.

36. 3.18 From 1980 to 2002, Americans were asked if they would feel safe traveling on a commercial airplane. A plot of the year versus the percentage that would feel safe is shown below. Comment on what is happening in the plot.
a) Evidence of
extrapolation
b) Evidence of a
regression outlier
c) Evidence of
confounding
d) Evidence of
nonresponse
Copyright © 2013 Pearson Education, Inc.

37. 3.18 From 1980 to 2002, Americans were asked if they would feel safe traveling on a commercial airplane. A plot of the year versus the percentage that would feel safe is shown below. Comment on what is happening in the plot.
a) Evidence of
extrapolation
b) Evidence of a
regression outlier
c) Evidence of
confounding
d) Evidence of
nonresponse
Copyright © 2013 Pearson Education, Inc.

38. 3.19 True or False: If two variables have a
correlation equal to 0.99, x must cause y.
a) True
b) False
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39. 3.19 True or False: If two variables have a
correlation equal to 0.99, x must cause y.
a) True
b) False
Copyright © 2013 Pearson Education, Inc.