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Message Posted: Wed, 02 Apr 2003 @ 08:21:18 GMT

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Hello,

here's the definition out of the documentation

SKEW ({DISTINCT} value_expression)

Value_expression is a column expression for which the skewness of the distribution of its values is to be computed. Returns the skewness of the distribution of value_expression. Is the measure of the asymmetry of the distribution about its mean compared with the normal distribution (i.e. skewness of 0).

Positive skewness indicates asymmetry extending toward more positive values.

Negative skewness indicates asymmetry extending toward more negative values.

The formula for SKEW(x) is as follows:

SKEW = (COUNT(x) /((COUNT(x) - 1) * (COUNT(x) 2)) * SUM(((x - AVG(x))/STDDEV_SAMP(x))**3

Ulrich Lickert

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