Coefficient of variation of two distributions are 60 and 70, and their standard deviation are 21
and 16 respectively. What are their means?

Coefficient of variation $=\frac{\sigma }{\overline{x}}\times 100$

For 1^st distribution : $60=\frac{21}{\overline{x}}\times 100$

$\Rightarrow \overline{x}=\frac{21\times 100}{60}=35$

For 2^nd distribution : $70=\frac{16}{\overline{x}}\times 100$

$\Rightarrow \overline{x}=\frac{16\times 100}{70}=22.85$

Hence, required means are 35, 22.85