JEE Main · 2026 · 02 Apr 2026 · Shift 2 · Statistics

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The mean and variance of observations are 8 and 16, respectively. If the sum of the first () observations is 48 and the sum of squares of the first () observations is 496, then the value of n is :
  1. (A)21
  2. (B)16
  3. (C)13
  4. (D)7✓ Correct

Answer: (D)

Solution

Let the -th observation be . The mean gives total , so . The variance gives , i.e. . Substituting ,

Since is a positive integer, .

JEE Main · 2026 · 02 Apr 2026 · Shift 2 · Single correct option

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