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
