Question

suppose the scores on an exam are normally distributed with a mean μ = 75 points and standard deviation σ = 8 points. what is the exam score for an exam whose z - score is 1.25? a. 65 b. 75 c. 85 d. 0.8944 e. 0.1056

Explanation:

Step1: Recall z - score formula

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

Step2: Rearrange formula for $x$

$x=\mu+z\sigma$.

Step3: Substitute values

$x = 75+1.25\times8=75 + 10=85$.

Answer:

C. 85