The average of 10 observations is 46. It was realised later that an observation was misread as 42 in place of 142. Find the correct average.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e 56.
The total of the 10 observations using the incorrect average = 46 × 10 = 460
Mistake = 142 was read as 42 → difference = 142 - 42 = 100
Correct total = 460 + 100 = 560
The correct average = 560 ÷ 10 = 56