The average weight of a group of 75 girls was calculated as 47 kgs. It was…
2025
The average weight of a group of 75 girls was calculated as 47 kgs. It was later discovered that the weight of one of the girls was read as 45 kgs. Whereas her actual weight was 25 kgs. What is the actual average weight of the group of 75 girls?
- A.
46.73 kg
- B.
46.64 kg
- C.
45.96 kg
- D.
None of these
Attempted by 53 students.
Show answer & explanation
Correct answer: A
Step 1: Compute the original total weight = 75 × 47 = 3525 kg.
Step 2: The recorded weight 45 kg was incorrect; the actual weight is 25 kg. Corrected total = 3525 − 45 + 25 = 3505 kg.
Step 3: Actual average = 3505 ÷ 75 = 46.733... kg ≈ 46.73 kg.
Alternatively, change in average = (wrong reading − actual reading) ÷ number of girls = (45 − 25) ÷ 75 = 20 ÷ 75 = 0.26666..., so new average = 47 − 0.26666... = 46.733... kg.
Answer: 46.73 kg (rounded to two decimal places).