The lengths of pregnancies are normally distributed with a mean of 264 days and a standard deviation of 15 days. If 36 women are randomly selected, find the probability that they have a mean pregnancy between 264
Days and 266 days.
A)0.2881
B)0.7881
C)0.2119
D)0.5517

Question

Quizplus · Accepted Answer

The probability that the mean pregnancy length is between 264 days and 266 days is given by the area under the normal distribution curve between these two values. Using the standard normal distribution (z-distribution), we have:z = (264 - 264) / 15 = 0z = (266 - 264) / 15 = 1.33P(0 < z < 1.33) = 0.2881Therefore, the probability that the mean pregnancy length is between 264 days and 266 days is 0.2881.

The Lengths of Pregnancies Are Normally Distributed with a Mean