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The mean of 20 observations is 15. On checking, it was found that two observation were wrongly copied as 3 and 6. If wrong observations are replaced by correct values 8 and 4 , then the correct mean is

Options

  1. A15
  2. B15.15
  3. C15.35
  4. D16

Correct answer

B. 15.15

Step-by-step solution

Difference in values =(8+4)-(6+3)=3 Mean difference = 3 20 =0.15 Hence, correct mean =15.15

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