Question

The sum of the squares of deviation of 10 observations from their mean 50 is 250, then coefficient of varition is

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

Answer 1

Answer: (A)

10%

Given $\Sigma {(x_i-\overline{x})}^2=250$,$n=10,\overline{x}=50$
Now, $\sigma =\sqrt{\frac{1}{n}\Sigma {(x_i-\overline{x})}^2}$
$=\sqrt{\frac{1}{10}\times 250}=5$
Hence coefficient of variation $=\frac{\sigma }{\overline{x}}\times 100=\frac{5}{50}\times 100=10$%