One classic use of the normal distribution is inspired by a letter to Dear Abbey in which a wife claimed to have given birth 308 days after a brief visit from her husband, who was serving in the Navy. The lengths of pregnancies are normally distributed with a mean of 268 days and a standard deviation of 15 days. Given this information. (i) the probability of a pregnancy lasting 308 days or longer is 0.0038.
(ii. The result suggests that the husband is not the father of the child.
A) (i) and (ii) are correct statements.
B) (i) is a correct statement but not (ii).
C) (ii) is a correct statement but not (i).
D) (i) and (i) are false statements.

Question

Quizplus · Accepted Answer

The probability of a pregnancy lasting 308 days or longer, given a normal distribution with a mean of 268 days and a standard deviation of 15 days, is indeed very low (0.0038), suggesting such an event is highly unlikely. This statistical rarity supports the suggestion that the husband might not be the father, given the traditional understanding of pregnancy durations.

One Classic Use of the Normal Distribution Is Inspired by a Letter