Question

The average weight of a group of 20 boys was calculated to be 65 kg and it was later discovered that the weight of a boy was misread as 76 kg instead of the correct weight 66 kg. The correct average weight was:

• A. 66 kg
• B. 63 kg
• C. 65.5 kg
• D. 64.5 kg

Answer 1

Answer:

D. 64.5 kg

Correct average weight = (20 × 65 - 76 + 66)/20 ⇒ 1290/20 ⇒ 64.5 kg