What is the z-score of sample X, if n = 4, mu= 32, SD =10, and E[X] =31?

$Z = \frac{E \left(X\right) - \mu}{\frac{s d}{\sqrt{n}}} = \frac{31 - 32}{\frac{10}{2}} = \frac{1}{5}$
$Z = \frac{E \left(X\right) - \mu}{\frac{s d}{\sqrt{n}}} = \frac{31 - 32}{\frac{10}{2}} = \frac{1}{5}$