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NTA Abhyas JEE Main2020MathematicsStatisticsPractice

If x 1 , x 2 , x 3 , x 4 , x 5 . . . . . . . x n are n observations such that ∑ i = 1 n x i 2 = 400 and ∑ i = 1 n x i = 100 , then the possible value of n among the following is

Options

  1. A18
  2. B20
  3. C24
  4. D27

Correct answer

D. 27

Step-by-step solution

We know that, σ 2 ≥ 0 ⇒ Σ x i 2 n - Σ x i n 2 ≥ 0 ⇒ 400 n - 10000 n 2 ≥ 0 ⇒ n ≥ 2 5

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