# What is the z-score of X, if n = 135, mu= 74, SD =3, and X =73?

Jan 23, 2016

$Z = \frac{73 - 74}{\frac{3}{\sqrt{135}}} = - \frac{\sqrt{135}}{3}$
We can use: $z = \frac{x - \mu}{\sigma}$ assuming we have $\sigma$
$z = \frac{x - \mu}{\frac{s}{\sqrt{n}}}$; where n is sample size...