Question

The following information relates to a sample of size $60$:
$\sum {x_i}^2=18000,\sum x_i=960$. The variance is

• A. $6.63$
• B. $16$
• C. $22$
• D. $44$

Answer 1

The correct option is D $44$

Required variance is, ${\sigma }^2=\frac{\sum x_i^2}{n}-{\left(\frac{x_i}{n}\right)}^2=\frac{18000}{60}-{\left(\frac{960}{60}\right)}^2=300-256=44$