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The arithmetic mean of 100 observations is 40 . Later, it was found that an observation '53' was wrongly read as ' 83 '. What is the correct arithmetic mean?

Options

  1. A39.8
  2. B39.7
  3. C39.6
  4. D39.5

Correct answer

B. 39.7

Step-by-step solution

Correct arithmetic mean =40+ (-83+53) 100 =40+ (-30) 100 =39.7 .

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