Question

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

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

Answer 1

Answer: (A)

$10$%

Sum of the squares of 10 observations = 250
Thus, variance $=\frac{250}{10}$ = 25
$\Rightarrow$ standard deviation $=\sqrt{variance}=5$
The coefficient of variation is defined as the ratio of the standard deviation to the mean of the sample.
Thus, coefficient of variation = $\frac{5}{50}=\frac{1}{10}$, i.e. 10%