Question

The length of time it takes to find a parking space at 9 A.M. follows a normal distribution with a mean of 4 minutes and a standard deviation of 3 minutes.

Sixty percent of the time, it takes more than how many minutes to find a parking space?

Answer 1

3.24 minutes

Explanation:

Use a calculator or chart to find the z-score.

P(Z > z) = 0.60

P(Z < z) = 0.40

z = -0.253

Find the time associated with the z-score.

z = (x − μ) / σ

-0.253 = (x − 4) / 3

x = 3.24