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NTA Abhyas JEE Main2020MathematicsStatisticsPractice

Let x 1 , x 2 … , x n be n observations such that ∑ x i 2 = 300 and ∑ x i = 90 . Then a possible value of n among the following is

Options

  1. A25
  2. B18
  3. C29
  4. D22

Correct answer

C. 29

Step-by-step solution

Variance = Σ x i 2 n - Σ x i n 2 ⇒ Σ x i 2 n ≥ Σ x i n 2 ⇒ n ≥ Σ x i 2 Σ x i 2 ⇒ n ≥ 8100 300 ⇒ n ≥ 27

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