The average weight of a group of 15 students is 70 kg. Five more students of weight 65 kg, 68 kg, 45 kg, 77 kg and 62 kg join the group. What is the change in the average weight (rounded off to the nearest integer) of the group?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. Decreases by 2 kg.
Total weight of the initial group = 15 × 70 = 1050 kg
Total weight of the five new students = 65 + 68 + 45 + 77 + 62 = 317 kg
New total weight of the group = 1050 + 317 = 1367 kg
New number of students = 15 + 5 = 20
New average weight = 1367/20 = 68.35 kg
Decrease in average weight = 70 - 68.35 = 1.65 = 2 kg (approx)