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The algebraic sum of the deviation of 20 observations measured from 30 is 2 . Then, mean of observations is

Options

  1. A28 . 5
  2. B30 . 1
  3. C30 . 5
  4. D29 . 6

Correct answer

B. 30 . 1

Step-by-step solution

Given that, Σ i = 1 20 x i - 30 = 2 ⇒   Σ i = 1 20 x i - Σ i = 1 20 30 = 2 ⇒  x ¯ = 20 · 30 20 + 2 2 0 =   30 + 0 .1 = 30 .1

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