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 ${\bar{x}}_1=\frac{{\sigma }_1}{c\cdot v_1}\times 100$
$=\frac{22}{55}\times 100$
$=\frac{2}{5}\times 100$
$=40$
and arithmetic mean $\overline{x_2}=\frac{{\sigma }_2}{c\cdot v_2}\times 100$
$=\frac{39}{65}\times 100$
$=\frac{39}{13}\times 20$
$=60$