Question 5 (14.9 points)
The length of pregnancies are normally distributed with a
mean of 268 days (u = 268 ) and a standard deviation of 15
days (o= 15).
A group of 36 pregnant women (n = 36) were in a
parenting class together. What is the probability that the
average pregnancy for the women lasted longer than 270
days?
21.2%
28.8%
55.2%
78.8%