Normal Distribution Probability 2

/in /by

Normal Distribution Probability 2

For the next two questions assume that X = Length of Pregnancy has a normal distribution with a mean of μX = 268 days and a standard deviation of σX = 15 days.

a)  What is the probability that a single woman will have a pregnancy that is less

than 260 days?  What is the Prob( Xi < 260 ) ?

b)  What is the probability that the average length of pregnancy in a group of n=25

women will be less than 260 days?  What is the Prob(x̄ < 260)