A student scores 70 in an exam with weight 3 and 80 in an exam with weight 1. What is the weighted average?
Answer and explanation
Correct answer: C. 72.5
- Step 1: Weighted sum = 70 x 3 + 80 x 1 = 290. Step 2. Divide by 4: 72.5. Answer: 72.5. Why not the others: 75: the unweighted mean was used. 290: the sum was not divided by the total weight. 77.5: the weights were swapped.
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