Question

If n = 10, $\overline{X}=12$ and ${\sum }_x^2=1530$, then the coefficient of variation is

• A. $36\%$
• B. $41\%$
• C. $25\%$
• D. none of these

Answer 1

The correct option is C

$25\%$

Standard deviation is expressed in the following manner :

$\sigma =\sqrt{\frac{1}{n}{\sum }_i{x}_i^2-(\overline{X}{)}^2}=\sqrt{\frac{1550}{10}-(12{)}^2}$

= $\sqrt{9}=3$

CV =$\frac{\sigma }{\overline{X}}\times 100$

= $\frac{3}{12}\times 100=25\%$