The duration (in days) of human pregnancies follows approximately the N(266,16) distribution. What proportion of pregnancy durations is more than 270 days?
A)0.334
B)0.401
C)0.599
D)0.621

Question

Quizplus · Accepted Answer

We need to find P(X > 270), where X follows N(266,16).
Using the standard normal distribution, we can calculate the z-score as:
z = (270-266)/4 = 1
P(Z > 1) = 0.159
Therefore, the proportion of pregnancy durations that is more than 270 days is:
1 - P(Z < 1) = 1 - 0.841 = 0.159
So, the answer is B)0.401.

The Duration (In Days) of Human Pregnancies Follows Approximately the N(266,16)