If the mean and the variance of the data
\begin{tabular}{|l|c|c|c|c|}
\hline Class & & & & \\
\hline Frequency & 3 & & 4 & 7 \\
\hline
\end{tabular}
are and 19 respectively, then the value of is
\begin{tabular}{|l|c|c|c|c|}
\hline Class & & & & \\
\hline Frequency & 3 & & 4 & 7 \\
\hline
\end{tabular}
are and 19 respectively, then the value of is
- (A)18
- (B)21
- (C)20
- (D)19✓ Correct
Answer: (D)
Solution
With class midpoints and total frequency , the mean is and the variance is . Setting the variance equal to gives the unique solution , and then . Hence .
JEE Main · 2026 · 23 Jan 2026 · Shift 2 · Single correct option