28) A professional baseball player changed his throwing motion to increase the velocity of his fastball. Before the change, the player threw his fastball at an average of 91 miles per hour. After the change in his throwing motion, the team watched him throw 64 fastballs with an average speed of 91.75 miles per hour and a standard deviation of 3 miles per hour. a. Specify the null and alternative hypotheses to determine whether the baseball player increased the speed of his fastball. b. Calculate the value of the test statistic and the p-value. c. At the 1% significance level, can you conclude that the baseball player has increased the speed of his fastball? Explain.