Question

The time it takes to complete a test is
normally distributed with a mean of 45
minutes and a standard deviation of 12
minutes. If Nick took an hour and 8 minutes
to complete the test, find his z-score to the
nearest hundredth of a second.
I

Answer 1

Answer:

The z-score is -3.08, approximately.

Step-by-step explanation:

The z-score is defined

$Z=\frac{x - \mu}{\sigma}$

Where $\mu$ is the mean, $\sigma$ is the standard deviation and $x$ the data value.

In this case, we have

$x=8\\\mu = 45\\\sigma=12$

Replacing values, we have

$Z=\frac{8-45}{12}=\frac{-37}{12} \approx -3.08$

Therefore, the z-score is -3.08, approximately.