on a standardized exam, the scores are normally distributed with a mean of 80 and a standard deviation of…

Explanation:

Step1: Recall z - score formula

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

Step2: Identify values

We are given that $\mu = 80$, $\sigma=25$, and $x = 90$.

Step3: Substitute values into formula

$z=\frac{90 - 80}{25}=\frac{10}{25}=0.4$

Answer:

$0.4$