A baseball​ pitcher's most popular pitch is a​ four-seamfastball. The data below represent the pitch speed​ (in miles per​hour) for a random sample of 15 of his​ four-seam fastballpitches.
85.5, 86.8, 93.1, 93.6, 88.7, 92.8, 86.4, 93.7, 89.9, 91.2,86.7, 93.9, 85.4, 87.4, 90.6
(a)
Using the correlation coefficient of the normal probability​plot, is it reasonable to conclude that the population is normally​distributed?
Since the absolute value of the correlation coefficient betweenthe expected​ z-scores and the ordered observed​ data, ____, ____(exceeds/ does not exceed) the critical value ___, it (is/ is not)reasonable to conclude that the data come from a population that isnormally distributed. (Round three decimal places)
(b) Construct and interpret a​ 95% confidence interval for themean pitch speed of the​ pitcher's four-seam fastball.
One can 95% confident that the mean pitch speed of the pitcher'sfour-seam fastball is between ___ and ___ miles per hour.
One can 90% confident that the mean pitch speed of the pitcher'sfour-seam fastball is between ___ and ___ miles per hour.
One can 99% confident that the mean pitch speed of the pitcher'sfour-seam fastball is between ___ and ___ miles perhour. Â
