Variance and Standard Deviation (Grade 11 NSC Matric Mathematics): Flashcards

Variance and standard deviation

Average squared distance from mean

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

Square root of variance

$\text{cm}^{2}$

Same as original data

Data widely spread

Data tightly clustered near mean

Non-negative

Calculate the mean