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If for a sample size of 10 , ∑ i = 1 10 x i - 5 2 = 350 and ∑ i = 1 10 x i - 6 =20 , then the variance is

Options

  1. A23
  2. B24
  3. C25
  4. D26

Correct answer

D. 26

Step-by-step solution

∑ i = 1 10 x i - 6 = 20 ⇒ Σ x i = 80 ∑ i = 1 10 x i 2 - 10 x i + 25 = 350 ⇒ ∑ i = 1 10 x i 2 = 350 + 800 - 250 = 900 Then, variance = 900 10 - 8 2 = 90 - 64 = 2 6

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