JEE Main · 2026 · 23 Jan 2026 · Shift 2 · Statistics

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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
  1. (A)18
  2. (B)21
  3. (C)20
  4. (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

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