Answer to Question #254875 in Statistics and Probability for Jazzy

Question

About what percent of products last 15 more days

Answer 1

Let us use the following example:

The shelf life of a particular dairy product is normally distributed with a mean of 12 days and a standard deviation of 3 days. About what percent of the products last 15 or more days?

$\mu = 12 \\ \sigma = 3 \\ P(X≥15) = 1 -P(X<15) \\ = 1 -P(Z < \frac{15-12}{3}) \\ = 1 -P(Z< 1) \\ = 1 -0.8413 \\ = 0.1587$