A baseball pitcher concerned about losing speed from his

Last updated: 6/23/2023

A baseball pitcher concerned about losing speed from his fastball undertook a new training regimen during the offseason His team s pitching coach measured the speed of 20 random fastballs in miles per hour thrown by the pitcher during spring training and compared it with a sample of 20 random fastballs thrown during the pitcher s last five starts in the previous season The results are shown in the following table Assume that the pitcher s fastball speeds had a standard deviation of 2 9 miles per hour both before and after the training regimen and that the speeds for both time periods are normally distributed Let the pitcher s fastball speeds in the previous season be the first sample and let the pitcher s fastball speeds in spring training be the second sample At the 0 05 level of significance is there evidence that the pitcher is throwing fastballs at higher speeds Find the test statistic rounded to two decimal places and the p value rounded to three decimal places Last Season s Fastball 92 91 96 94 92 94 92 95 This Season s Fastball 90 95 93 94 91 95 97 92