Question

The coefficient of variation of two distributions are $60$ and $70.$ The standard deviations are $21$ and $16$ respectively, then their mean is

• A. $35$
• B. $23$
• C. $28.25$
• D. $22.85$

Answer 1

Answer: (A), (C), (D)

The correct options are
A $35$
C $28.25$
D $22.85$

Coefficient of Variation$=\frac{\sigma }{\mu }\times 100$

$\frac{{\sigma }_1}{{\mu }_1}\times 100=60\Rightarrow \frac{21}{{\mu }_1}\times 100=60\Rightarrow {\mu }_1=35$

$\frac{{\sigma }_2}{{\mu }_2}\times 100=70\Rightarrow \frac{16}{{\mu }_1}\times 100=70\Rightarrow {\mu }_2=\frac{160}{7}$