Students of two sections A and B of a class show the following results in a test conducted for 100 marks.…
Students of two sections A and B of a class show the following results in a test conducted for 100 marks.
\begin{array}{|l|c|c|}
\hline & Section A & Section B \\
\hline Number of students & 50 & 60 \\
\hline \begin{array}{l}
Average marks in the \\
test
\end{array} & 45 & 45 \\
\hline \begin{array}{l}
Variance of distribution \\
of marks
\end{array} & 64 & 81 \\
\hline
\end{array}
Then
variability of section $B>$ variability of section $A$
variability of section $A>$ variability of section $B$
variability of section $A=$ variability of section $B$
The data is not sufficient to compare the variability of the sections
Solution
$\because$ Average marks of section A and section B in the test is same, but the variance of distribution of marks of section $\mathrm{B}$ is greater than section $\mathrm{A}$.
$\therefore$ Variability of section $B>$ variability of section $A$.