Question

The average weight of 12 boys is 68 kg. Later it was found that the weight of one of the student was taken as 54 kg instead of 45 kg. Find the actual average weight of the group.
1. 66.25 kg
2. 66.5 kg
3. 67.25 kg
4. 67.5 kg
5. 50.25 kg

Answer 1

Correct Answer - Option 3 : 67.25 kg

Given:

Average weight of 12 boys = 68 kg

Wrong weight of one boy = 54 kg

Actual weight = 45 kg

Formula used:

Average = sum of observations/total number of observations

Calculation:

Total weight = 12 × 68 = 816 kg

Actual weight = 816 - 54 + 45 = 807

∴ Actual average = 807/12 = 67.25 kg

∴ The average is 67.25 kg