Question

The coefficients of variation of two series are $58$% and $69$%. If their standard deviations are $21.2$ and $15.6$, then their A.M's are

• A. $36.6,22.6$
• B. $34.8,22.6$
• C. $36.6,24.4$
• D. None of these

Answer 1

The correct option is A $36.6,22.6$

We know that $C.V.=\frac{\sigma \times 100}{\overline{x}}\Rightarrow \overline{x}=\frac{\sigma }{C.V.}\times 100$
$\therefore$ Mean of first series $=\frac{21.2\times 100}{58}=36.6$
Mean of second series $=\frac{15.6\times 100}{69}=22.6$