the average weight of students in marks class is 150 pounds, with a standard deviation of 10 pounds. mark…

Explanation:

Step1: Recall z - score formula

The z - score formula 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 $x = 170$ (Mark's weight), $\mu=150$ (average weight), and $\sigma = 10$ (standard deviation).

Step3: Substitute values into formula

$z=\frac{170 - 150}{10}=\frac{20}{10}=2$

Answer:

A. 2.0