Suppose the lengths of the pregnancies of a certain animal are approximately normally distributed with mean mu equals 198 daysμ=198 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 191191 days? the probability that a randomly selected pregnancy lasts less than 191191 days is approximately

We are given:
Population mean = u = 198
Population Standard Deviation = s = 20

Since population standard deviation is known, we will use z-distribution to solve this problem.

To find the probability that the pregnancy lasts less than 191 days, we have to first convert it into z score.



So z score will be = - 0.35

From the z table, the probability of z score to be less than – 0.35 is 0.3632

Therefore, we can conclude that probability that a randomly selected pregnancy lasts less than 191 days is approximately 0.3632.