The lengths of pregnancies of humans are normally distributed with a mean of 268 days and a standard deviation of 15 days. Find the probability of a pregnancy lasting less than 250 days.

A) 0.0066.

B) 0.0606.

C) 0.1151.

D) 0.1591.

Answer: C) 0.1151.

Step-by-step explanation:

Hi, to answer this question we have to apply the formula

P = 2w + 2 L

Where:

P=perimeter

W = width

Hi, to answer this question we have to calculate the z score:

z = (X-μ / σ)

Where:

X: variable

μ : mean

σ:standard deviation

Replacing with the values given and solving:

P (X <250) = P (X-μ / σ < [250-268] / 15)

P = z <-1.2

the probability (P) associated with a z-score of - 1.2 is C) 0.1151. (looking in the table of z-scores)