Suppose the lengths of the pregnancies of a certain animal are approximately normally distributed with mean μ = 238 days and standard deviation σ = 13 days. Complete parts (a) through (f) below.
(a) What is the probability that a randomly selected pregnancy lasts less than 234 days?
The probability that a randomly selected pregnancy lasts less than 234 days is approximately 0.3792. (Round to four decimal places as needed.)
Interpret this probability. Select the correct choice below and fill in the answer box within your choice. (Round to the nearest integer as needed.)
A. If 100 pregnant individuals were selected independently from this population, we would expect pregnancies to last more than 234 days.
B. If 100 pregnant individuals were selected independently from this population, we would expect pregnancies to last exactly 234 days.
C. If 100 pregnant individuals were selected independently from this population, we would expect pregnancies to last less than 234 days.
(b) Suppose a random sample of 18 pregnancies is obtained. Describe the sampling distribution of the sample mean length of pregnancies.
The sampling distribution of x̄ is normal with μ_x̄ = and σ_x̄ = .
(Round to four decimal places as needed.)
(c) What is the probability that a random sample of 18 pregnancies has a mean gestation period of 234 days or less?
The probability that the mean of a random sample of 18 pregnancies is less than 234 days is approximately .
(Round to four decimal places as needed.)