The lengths of pregnancies are normally distributed with a mean of 268 days and a standard deviation of 15 days. If 64 women are randomly selected, find the probability that they have a mean pregnancy between 266
Days and 268 days.
A)0.3577
B)0.7881
C)0.2881
D)0.5517

Question

Quizplus · Accepted Answer

The probability that the mean pregnancy is between 266 days and 268 days is the area under the normal distribution curve between z-scores of -1.33 and 1.33. This area is 0.3577.

The Lengths of Pregnancies Are Normally Distributed with a Mean