Var_Samp

This function calculates the sample variance of a set of numbers after discarding NULL values from this set. It uses the following formula: (Sum(X^2) - Sum(X)^2/Quantity(X))/(Quantity(X) - 1).

If Quantity(X) = 1, the return value is NULL.

Syntax:

Var_Samp(Expression)

Parameter:

Expression. Type: Number. 

Example:

X	Y
1	7
2	1
3	2
4	5
5	7
6	34
7	32
8	43
9	87

SELECT Var_Samp(Y, X) FROM Table

Result:

805.694444

Next page: Var_Pop