Question

${\sigma }^2$ is known as

• A. mean
• B. variance
• C. Standard deviation
• D. quartile deviation

Answer 1

The correct option is B variance

Variance gives the degree to which the numerical data tend to spread about the value.

Variance is denoted by ${\sigma }^2$

Variance is given by $\frac{\sum x^2}{n}-(\frac{\sum x}{n}{)}^2$

But mean $\overline{x}=\frac{\sum x}{n}$

Therefore, variance is $\frac{\sum x^2}{n}-(\overline{x}{)}^2$