1. Copyright © 2009 Pearson Education, Inc.
Chapter 7
Correlation and Causality
Active Learning Questions
For use with classroom response systems
Copyright © 2009 Pearson Education, Inc.

2. The heights of men and their shoe sizes have a
a. Positive correlation
b. Negative correlation
c. Zero correlation

3. The heights of men and their shoe sizes have a
a. Positive correlation
b. Negative correlation
c. Zero correlation

4. Is the correlation n = 18, r = –0.551 at the 0.01 level significant?
Required for Significance at n
0.05 level
0.01 level 10
.632
.765 15
.514
.641 18
.468
.590 50
.279
.361 80
.220
.286
a. Significant b. Not Significant

5. Is the correlation n = 18, r = –0.551 at the 0.01 level significant?
Required for Significance at n
0.05 level
0.01 level 10
.632
.765 15
.514
.641 18
.468
.590 50
.279
.361 80
.220
.286
a. Significant b. Not Significant

6. Is the correlation n = 80, r = 0.347 at the 0.05 level significant?
Required for Significance at n
0.05 level
0.01 level 10
.632
.765 15
.514
.641 18
.468
.590 50
.279
.361 80
.220
.286
a. Significant b. Not Significant

7. Is the correlation n = 80, r = 0.347 at the 0.05 level significant?
Required for Significance at n
0.05 level
0.01 level 10
.632
.765 15
.514
.641 18
.468
.590 50
.279
.361 80
.220
.286
a. Significant b. Not Significant

8. Choose the best value of r based on the diagram.
a. 0.8 b c. –0.8 d. –0.98

9. Choose the best value of r based on the diagram.
a. 0.8 b c. –0.8 d. –0.98

10. Choose the point that would be an outlier if it were plotted on the graph.
a. (2, 4) b. (5, 10) c. (7, 8) d. (11, 4)

11. Choose the point that would be an outlier if it were plotted on the graph.
a. (2, 4) b. (5, 10) c. (7, 8) d. (11, 4)

12. Which graph illustrates a set of data that consists of two groups of data that are each negatively correlated, but overall has correlation near zero? a. b. c. d.

13. Which graph illustrates a set of data that consists of two groups of data that are each negatively correlated, but overall has correlation near zero? a. b. c. d.

14. Select the probable cause of correlation between the variables
Select the probable cause of correlation between the variables. The x variable is the weight of a
football halfback and the y variable is his average yards per game for a season.
a. Heavier players gain more yards.
b. Heavier players gain fewer yards.
c. There is no correlation.
d. The relationship is coincidental.

15. Select the probable cause of correlation between the variables
Select the probable cause of correlation between the variables. The x variable is the weight of a
football halfback and the y variable is his average yards per game for a season.
a. Heavier players gain more yards.
b. Heavier players gain fewer yards.
c. There is no correlation.
d. The relationship is coincidental.

16. Select the best fit line from the three lines below.
a. A b. B c. C

17. Select the best fit line from the three lines below.
a. A b. B c. C

18. The best fit line in the diagram has a correlation coefficient r =0
The best fit line in the diagram has a correlation coefficient r = Find the percent of the variation in y that is NOT explained by the linear relationship between x and y.
a. 10.4% b. 89.6% c. 1.08% d %

19. The best fit line in the diagram has a correlation coefficient r =0
The best fit line in the diagram has a correlation coefficient r = Find the percent of the variation in y that is NOT explained by the linear relationship between x and y.
a. 10.4% b. 89.6% c. 1.08% d %

20. From the graph below, use the best fit line to predict the value of y at x = 30.
a. 18 b. 19 c. 20 d. 22

21. From the graph below, use the best fit line to predict the value of y at x = 30.
a. 18 b. 19 c. 20 d. 22