Question

On a standardized exam, the scores are normally distributed with a mean of 190 anda standard deviation of 20. Find the z-score of a person who scored 155 on the exam.

Answer 1

Step 1

State an expression for the z-score

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

Where

$\begin{gathered} \mu=\operatorname{mean}=190 \\ \sigma=\text{ Standard deviation}=20 \end{gathered}$

Step 2

Find the z-score when x = 155

$undefined$