Question

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

• A. 10%
• B. 40%
• C. 50%
• D. none of these

Answer 1

The correct option is A 10%

$\text{Coefficient of variation}=\frac{\sigma }{x}\times 100=\frac{\sigma }{50}\times 100[\because \overline{x}=50]=2\sigma \text{Also,}\sigma =\sqrt{\frac{\sum (x_i-50{)}^2}{n}}=\sqrt{\frac{250}{10}}=\sqrt{25}=5\therefore \text{Coefficient of variation}=2\times 5=10\%$