Question

The time required to finish a test is normally distributed with a mean of 60 minutes and a standard deviation of 10 minutes. What is the z-Score for a student who finishes the test in 45 minutes?

Answer 1

`z = -1.5`

Explanation:

Since we know the time required to finish the test is normally distributed, we can find the `z`-score for this particular time.

The formula for a `z`-score is `z = (x - mu)/sigma`, where `x` is the observed value, `mu` is the mean, and `sigma` is the standard deviation.

`z = (45 - 60)/10`

`z = -1.5`

The student's time is `1.5` standard deviations below the mean.