Z-Score Calculation: Understanding 'z x - mu / sigma'

The expression 'z x - mu / sigma' can be interpreted as the standard score or z-score of a data point x, given the mean mu and standard deviation sigma.

The formula to calculate the z-score is:

z = (x - mu) / sigma

In this case, z x - mu / sigma can be rewritten as:

z = (x - mu) / sigma

So, the expression is simply the formula for calculating the z-score.