Z score of mean
From OPOSSEM
<math>Z = \frac {\bar{y}-\mu_0}{\frac {s_\bar{y}}{\sqrt{n-1}}}</math>, where <math>\mu_0 </math> is the test value.
<math>Z = \frac {\bar{y}-\mu_0}{\frac {s_\bar{y}}{\sqrt{n-1}}}</math>, where <math>\mu_0 </math> is the test value.