Standard Deviation & Variance (AQA A-Level Mathematics): Quizzes

Average deviation from the mean

$\sigma^2$ (mean square deviation)

Standard deviation is square root of variance

$\sigma^2 = \frac{\Sigma (x - \bar{x})^2}{n}$

Mean of all squared data

To make deviations positive

Standard deviation ($\sigma$)

Interquartile range (IQR)

Range

$3.5$