Question

Coefficient of variations of two distributions are $55$ and $65$, and their standard deviations are $22$ and $39$ respectively. Their arithmetic means are respectively

• A. 15, 20
• B. 40, 60
• C. 30, 50
• D. None of these

Answer 1

Answer: (B)

Given that, coefficient of variations of two distributions are
$C\cdot V_{1}=55, c\cdot v_{2}=65$
and $\sigma_{1}=22, \sigma_{2}=39 $
Then, arithmetic mean $\bar{x}_{1}=\frac{\sigma_{1}}{c\cdot v_{1}}\times100 $
$=\frac{22}{55}\times100$
$=\frac{2}{5}\times100$
$=40$
and arithmetic mean $\bar{x_{2}}=\frac{\sigma_{2}}{c\cdot v_{2}}\times100$
$=\frac{39}{65}\times100$
$=\frac{39}{13}\times20$
$=60$