Question 381446
The mean of X may not be 0, the mean of Z is 0.  The standard deviation of Z may not be 1, the sd of Z is 1.  To switch from X to Z (or vice-versa) we use the formula (commonly called the "z-score") {{{Z = (X - mu)/sigma}}}, where {{{mu}}} is the mean of X , and {{{sigma}}} is the standard deviation of X.