Question

The sum of square of deviations for $10$ observations taken from mean $50$ is $250$. The coefficient of variation is

• A. 10
• B. 20
• C. 30
• D. 40

Answer 1

Answer: (A)

We know the formula
${\sigma }^2=\frac{\sum {(x-x)}^2}{n}$
$\Rightarrow$ ${\sigma }^2=\frac{250}{10}$
$\Rightarrow$ $\sigma =5$
$\therefore$ Coefficient of variation
$CV=\frac{\sigma }{x}\times 100$
$\Rightarrow$ $CV=\frac{5}{50}\times 100$
$\Rightarrow$ $CV=10$