Multiple choice

The average of 100 observation was calculated as 35. It was found later, that one of the observations was misread as 83 instead of 53. The correct average is

  1. $32.7$
  2. $34.7$
  3. $35.7$
  4. $36.7$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total of 100 observations = 100 × 35 = 3500. Correct total = 3500 - 83 + 53 = 3470. Correct average = 3470 / 100 = 34.7. The difference of 30 (83 - 53) distributed over 100 observations changes average by 0.3. Option B is correct.

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