## Definition

The variance is the statistical indicator which measures the distance of a time series around the mean of the latter.

## Calculation

Variance = Average of the squares of the deviations from this average

With V the variance, n the number of samples, x "i" the value of the sample and x "bars" the mean of the series

## Example

For a product that has sold:

- 100 produced in 2017
- 150 products in 2018
- 200 products in 2019
- The average is 150 products sold
- The mean of the squared deviations is ((100-150) ² + (150-150) ² + (200-150) ²) = 2500 + 0 + 2500 = 5000

## Terminology

The variance is translated in English by variance

## Declination

Standard deviation is often used alongside variance. It is the square root of the variance. Here, it is worth 71. Thus the product is sold on average 150 times more or less 71.

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