Multiple choice general knowledge math & puzzles

The mean of 20 observations was found to be 65 but later on it was found that 69 was misread as 96.Find the correct mean..?

  1. 63.65

  2. 65.95

  3. 67.5

  4. 69.5

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Original sum = 20 × 65 = 1300. But 96 was recorded instead of 69, so error = 96 - 69 = 27. Correct sum = 1300 - 27 = 1273. Correct mean = 1273/20 = 63.65. This matches option A. Option B (65.95) would result if we added 27 instead of subtracting.