Multiple choice

The table below gives information about the number of students in a class having different average weights (assume no student's weight is accounted more than once in determining the indicated average weights) Number of Students 3 3 5 3 1 1 5 3 Average Weight 58 60 62 64 66 68 70 72 What is the average weight of the students in the class?

  1. 65.92 kg

  2. 64.83 kg

  3. 62.31 kg

  4. 63.13 kg

  5. e
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B Correct answer
Explanation

Weighted average = sum(weight * count) / total count. Total count = 3+3+5+3+1+1+5+3 = 24. Sum = (3*58 + 3*60 + 5*62 + 3*64 + 1*66 + 1*68 + 5*70 + 3*72) = 174 + 180 + 310 + 192 + 66 + 68 + 350 + 216 = 1556. Average = 1556 / 24 = 64.833.

AI explanation

To find the overall average weight, calculate the total weight by multiplying the number of students by their respective average weights and summing the products. The total weight is (3 times 58) plus (3 times 60) plus (5 times 62) plus (3 times 64) plus 66 plus 68 plus (5 times 70) plus (3 times 72), which equals 174 plus 180 plus 310 plus 192 plus 66 plus 68 plus 350 plus 216, resulting in 1556. The total number of students is 3 plus 3 plus 5 plus 3 plus 1 plus 1 plus 5 plus 3, which is 24. The overall average weight is 1556 divided by 24, which equals 64.83 kg.

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