Homework fro pregnancy days

Question

Suppose the lengths of the pregnancies of a certain animal are approximately normally distributed with mean

mu equals 191 daysμ=191 days

and standard deviation

sigma equals 20 daysσ=20 days.

Complete parts​ (a) through​ (f) below.

(a) What is the probability that a randomly selected pregnancy lasts less than

183183

​days?

Answer 1

It looks like this question wants you to find the z score and then use that number to find the probability of x.

z = (x - µ)/σ

z = (183 - 191)/20

z = -0.4

Using a z-table or other z-score/percentile calculators, you will find that a z-score of -0.4 has a corresponding probability of 0.3446. Thus, P(x<183) = 0.3446 = 34.46%