Purpose: The purpose of this program is to calculate z-scores for either sample (i.e., single) observations or for sample means. In each case the formula is displayed.

Download: You can download this program from within Stata by typingsearch zcalc(see How can I use the search command to search for programs and get additional help? for more information about usingsearch).

Use of program: To use this program, in the Stata command window typezcalcand then either (1) three numbers indicating x (i.e., the value of an observation), the mean and the standard deviation, or (2) four numbers, indicating the mean, mu, the standard deviation and n (i.e., the sample size).

Examples: The following example shows how to usezcalcto calculate the z-score for a single observation. In this example, x(observation) = 20, mean = 10 and standard deviation = 50.

The following example shows how to use

zcalcto calculate the z-score for sample means. In this example, the mean = 20, mu = 10, the standard deviation = 50 and n = 50.