In Chapter 4 #25, you compared the distributions of innings per game for 24 starting pitchers in 1958 and 99 starting pitchers in 2008. Do the data provide convincing evidence that pitchers in 1958 had a greater ability to
stay in games?
a. State the hypotheses we are interested in testing.
b. The mean innings per game in 1958 was 6.70 and the mean innings per game in 2008 was 6.05 for a test
statistic of 6.70 – 6.05 = 0.65. Describe how to simulate the distribution of the test statistic, assuming that
pitchers in both years have the same ability to stay in games.
c. A simulation was conducted assuming that pitchers both years have the same ability to stay in games. In each
of the 100 trials, the difference in means was calculated and recorded on the dotplot below. Use the dotplot to
estimate and interpret the p-value.
d. Based on the p-value, make an appropriate conclusion.
e. If there is convincing evidence that pitchers in 1958 did have a greater ability to stay in games, does that mean
today’s pitchers are wimpier? What other possible explanations could there be?