Question

The average weight of 23 students is 42 kg. The weight of one student was misread as 63 instead 36. Find the correct average weight.
1. 48 kg
2. 40.82 kg
3. 38.82 kg
4. 50 kg

Answer 1

Correct Answer - Option 2 : 40.82 kg

Given

Average weight of 23 students = 42 kg

Formula used

Average = Sum of all observations/Number of observation

Calculations

Sum of 23 observations = 23 × 42

⇒ 966 kg

Correct sum = (Total value - wrong value + correct value)

= (966 - 63 + 36)

= 966 - 27

= 939

Correct average weight  = 939/23

⇒ 40.82

∴  Correct average weight  of 23 students is 40.82 kg.