Question

In a final examination in Statistics the mean marks of a group of $150$ students were $78$ and the S.D was $8.0$. In Economics, however, the mean marks were $73$ and the S.S was $7.6$. The variability in the two subjects respectively is

• A. $10.3\%,10.4\%$
• B. $95\%,7.9\%$
• C. $11.2\%,10.1\%$
• D. none of these

Answer 1

Answer: (A)

$10.3\%,10.4\%$

Coefficient of variance $=\frac{\sigma }{\overline{x}}\times 100$
For Statistics, $\sigma =8,\overline{x}=78$
So, coefficient of variation $=\frac{8}{78}\times 100=10.3$%
For economics, $\sigma =7.6,\overline{x}=73$
So, coefficient of variation $=\frac{7.6}{73}\times 100=10.4$%