the average height of students in courtneys class is 5.5 feet, with a standard deviation of 0.4 feet…

Explanation:

Step1: Recall z - score formula

The formula for the z - score is $z=\frac{x-\mu}{\sigma}$, where $x$ is the value, $\mu$ is the mean, and $\sigma$ is the standard deviation.

Step2: Identify values

We have $x = 6.1$ (Courtney's height), $\mu=5.5$ (mean height), and $\sigma = 0.4$ (standard deviation).

Step3: Substitute values into formula

$z=\frac{6.1 - 5.5}{0.4}=\frac{0.6}{0.4}=1.5$

Answer:

A. 1.5