Question

If the variance of a set is $9$ and coefficient of variation is $20,$ then the mean of that set is

• A. $45$
• B. $18$
• C. $15$
• D. $9$

Answer 1

The correct option is C $15$

Coefficient of variation $=\frac{\sigma }{\mu }\times 100$
where $\sigma$ is the standard deviation and $\mu$ is the mean of the set.
$\sigma =\sqrt{9}=3$
$\therefore \mu =\frac{3}{20}\times 100=15$