Standard Deviation & Variance

Variance

Measure of how data points vary from the mean

Variance

A measure of how far a set of data are dispersed out from their mean or average value

Variance

It is denoted as “σ2”

Non-negative

Variance is always _____ since each term in the variance sum is squared and therefore the result is either positive or zero

squared

Variance always has _____ units.

Standard Deviation

The measure of the distribution of statistical data

Standard Deviation

It is denoted by the symbol “σ”

Variance

Is equal to the average squared deviations from the mean, while standard deviation is the number’s square root.

Standard Deviation

The square root of variance