Skewness

Use USTATS or TABLES with STATS=USTATS to compute the skewness of a variable.

To test departures from normality: for N greater than 150, refer the critical ratio of the skewness measure to a table of the unit normal curve; for N between 25 and 150, refer the skewness measure to a table for testing skewness.

Note that the skewness measure is a biased estimator.