Baseballs vary somewhat in their rebounding coefficient. A baseball that has a large rebound coefficient will travel farther when the same force is applied to it than a ball with a smaller coefficient. To achieve a game in which each batter has an equal opportunity to hit a home run, the balls should have nearly the same rebound coefficient. A standard test has been developed to measure the rebound coefficient of baseballs. A purchaser of large quantities of baseballs requires that the mean coefficient value be 85 units and the standard deviation be less than 2 units. A random sample of 40 baseballs is selected from a large batch of balls and tested. The data are given here.

84.8 88.1 85.1 88.0 86.6 85.3 85.1 91.4 83.4 87.2 83.7 89.5 85.6 83.5 81.6 81.1 83.6 81.2 84.7 87.0 87.5 84.3 86.9 83.3 85.9 82.2 88.2 83.5 82.7 86.0 87.3 87.9 82.6 80.5 85.6 82.3 79.3 84.9 80.6 83.9