The average weight of a group of 75 girls was calculated as 47 kg. It was…

2024

The average weight of a group of 75 girls was calculated as 47 kg. It was later discovered that the weight of one of the girls was read as 45 kg, whereas her actual weight was 25 kg. What is the actual average weight of the group of 75 girls? (Rounded off to two digits after decimal )

  1. A.

    46.73 kg

  2. B.

    46.64 kg

  3. C.

    45.96 kg

  4. D.

    None

Attempted by 37 students.

Show answer & explanation

Correct answer: A

Step 1: Find the recorded total weight using the given average: 75 × 47 = 3525

Step 2: Correct the recorded total by removing the excess caused by the misread weight. The weight was read as 45 kg instead of 25 kg, so the recorded total is 20 kg too large:

  • Corrected total = 3525 − (45 − 25) = 3525 − 20 = 3505

Step 3: Compute the actual average:

  • Actual average = 3505 ÷ 75 = 46.733333...

Final answer: 46.73 kg

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