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Question 1 10.40

Do the accompanying data provide sufficient evidence to conclude that a straight line is useful for characterizing the relationship between x and y?

x	4	2	4	3	2	4
y	1	6	5	3	2	4

Question 2 10.58

In business, do nice guys finish first or last? Refer to the Nature (March 20, 2008) study of the use of punishment in cooperation games, Exercise 10.14 (p.572). Recall that college students repeatedly played a version of the game “prisoner’s dilemma,” and the researchers recorded the average payoff and the number of times cooperation, defection, and punishment were used for each player.

a. A test of no correlation between cooperation use (x) and average payoff (y) yielded a p-value of .33. Interpret this result.

b. A test of no correlation between defection use (x) and average payoff (y) yielded a p-value of .66. Interpret this result.

c. A test of no correlation between punishment use (x) and average payoff (y) yielded a p-value of .001. Interpret this result.

Question 3 11.26

Predicting runs scored in baseball. Refer to the Chance (Fall 2000) study of runs scored in Major League Baseball games,  Exercise 11.14  (p.  640 ). Multiple regression was used to model total number of runs scored (y) of a team during the season as a function of number of walks (x1), number of singles (x2), number of doubles (x3), number of triples (x4), number of home runs (x5), number of stolen bases (x6), number of times caught stealing (x7), number of strikeouts (x8), and total number of outs (x9). Using the β estimates given in  Exercise 11.14 , predict the number of runs scored by your favorite Major League Baseball team last year. How close is the predicted value to the actual number of runs scored by your team? [Note: You can find data on your favorite team on the Internet at  www.mlb.com .]

Exercise 11.14 --->(a sample of n = 234), the results in the next table were obtained.

Independent Variable	β Estimate	Standard Error
Intercept	3.70	15.00
Walks (x1)	.34	.02
Singles (x2)	.49	.03
Doubles (x3)	.72	.05
Triples (x4)	1.14	.19
Home runs (x5)	1.51	.05
Stolen bases (x6)	.26	.05
Caught stealing (x7)	–.14	.14
Strikeouts (x8)	–.10	.01
Outs (x9)	–.10	.01