The MEANS procedure provides data summarization tools to compute descriptive statistics for variables across all observations and within groups of observations. For example, PROC MEANS: calculates descriptive statistics based on moments; estimates quantiles, which includes the median; calculates confidence limits for the mean; identifies extreme values; performs a t test. By default, PROC MEANS displays output. You can also use the OUTPUT statement to store the statistics in a SAS data set. PROC MEANS and PROC SUMMARY are very similar; see The SUMMARY Procedure for an explanation of the differences.