Question

The sum of the squares of deviations of 10 items about mean 50 is 250 .The coefficient of variation is

• A. 10%
• B. 50%
• C. 30%
• D. none of these

Answer 1

The correct option is A 10%

Given, $\sum (x-\overline{x}{)}^2=250,n=10,\overline{x}=50$
Thus standard deviation $=\sqrt{\frac{\sum (x-\overline{x}{)}^2}{n}}=\sqrt{25}=5$
$\therefore$ Coefficient of variation $=\frac{\sigma }{\overline{x}}\times 100=\frac{5}{50}\times 100$ % $=10$%