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The mean of a group of 100 observations was found to be 20 . Later it was found that four observations were incorrect, which were recorded as 21,21,18 and 20 . What is the mean if the incorrect observations are omitted?

Options

  1. A18
  2. B20
  3. C21
  4. D22

Correct answer

B. 20

Step-by-step solution

aligned & Mean of 100 observations =20 & Required mean = 20 100-(21+21+18+20) 96 & = 1920 96 =20 aligned

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