The arithmetic mean of 100 observations was 50. Later on, it was found that two observations were misread as 82 and 6 instead of 182 and 56. What is the value of the corrected mean?

  1. A. 50.1
  2. B. 51.5
  3. C. 52.3
  4. D. 53.4

Correct Answer: B. 51.5

Explanation

The original sum of observations is 100 \times 50 = 5000. The net increase required to correct the errors is (182 - 82) + (56 - 6) = 100 + 50 = 150. The corrected sum is 5150, making the corrected mean 5150 / 100 = 51.5.

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