Question

if the mean is 40, the standard deviation is 8, and ( x ) is 80, then find the z-score.

a 5

b 4

c 7

d 6

Explanation:

Step1: Recall z - score formula

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

Step2: Substitute the given values

We are given that $\mu = 40$, $\sigma=8$, and $x = 80$. Substituting these values into the formula, we get $z=\frac{80 - 40}{8}$.

Step3: Simplify the expression

First, calculate the numerator: $80 - 40=40$. Then, divide by the denominator: $\frac{40}{8} = 5$.

Answer:

a. 5