# Variance

The **Variance **function computes the statistical variance of a column or group. It is a measure of dispersion or how far the set of observations (numbers) varies from the mean and is calculated as the average squared differences from the mean. A small variance suggests the data points tend to be close to the mean and from one another, whereas a high variance suggests the data points tend to lie farther from the mean and from one another.

*Sigma calls the underlying Cloud Data Warehouse's Variance function that uses the statistical*

**sample**definition. Check the documentation of the database you use for details on the function called.## Syntax

Variance(column)

Function arguments:

**column**(required) - The column of numbers to calculate the variance of. Any`null`

values are skipped.

The underlying formula is as follows:

(x_i-x)^2/n-1

where x_i is the value of one observation, x is the mean value of all observations, and n is the number of observations (sample size).

## Example

Variance([x])

- Return the sample variance of non-null records in the
*x*column for each group*K*.