Measures of Spread (VCE SSCE Mathematical Methods): Flashcards

How far values fall from the mean

$\sigma^2$

$\sqrt{\text{Var}(X)}$

$\sigma$

$\text{Var}(X) = E(X^2) - \mu^2$

Same units

$Q_3 - Q_1$

Spread of middle 50% of distribution

25th percentile (first quartile)

75th percentile (third quartile)