Question

the length of human pregnancies is approximately normal with mean \\( \mu = 266 \\) days and standard deviation \\( \sigma = 16 \\) days. complete parts (a) through (f)\
click here to view the standard normal distribution table (page 1). click here to view the standard normal distribution table (page 2).\
(a) what is the probability that a randomly selected pregnancy lasts less than 250 days?\
the probability that a randomly selected pregnancy lasts less than 250 days is approximately \\( \square \\)\
(round to four decimal places as needed.)

Explanation:

Step1: Calculate the z-score

The formula for the z-score is $z = \frac{x - \mu}{\sigma}$, where $x = 250$, $\mu = 266$, and $\sigma = 16$.
Substitute the values: $z = \frac{250 - 266}{16} = \frac{-16}{16} = -1$.

Step2: Find the probability from z-table

We need to find $P(Z < -1)$. Looking at the standard normal distribution table, the area to the left of $z = -1$ is 0.1587.

Answer:

0.1587