The population of lengths of aluminum-coated steel sheets is normally distributed with a mean of 30.05 inches and a standard deviation of .2 inches. What is the probability that a sheet selected at random from the population is between 30.25 and 30.65 inches long?
A) .9987
B) .1574
C) .1587
D) .8413

Question

Quizplus · Accepted Answer

P([30.25 − 30.05]/.2 ≤ z ≤ (30.65 − 30.05)/.2) = P(1 ≤ z ≤ 3.0) = .9987 − .8413 = .1574

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