The population of lengths of aluminum-coated steel sheets is normally distributed with a mean of 30.05 inches and a standard deviation of .3 inches. What is the probability that the average length of a steel sheet from a sample of 9 units is more than 29.95 inches long?
A) .8413
B) .6293
C) .3707
D) .1587

Question

Quizplus · Accepted Answer

P[z > (29.95 − 30.05)/(.3/)] = P(Z > −1) = 1.00 − .1587 = .8413

The Population of Lengths of Aluminum-Coated Steel Sheets Is Normally