Multiple choice

The average grade of a section of 20 students is 66% and that of another section of 15 students is 70%. What is the combined mean grade?

  1. 66.7%

  2. 67.7%

  3. 68.7%

  4. 69.7%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Use the weighted mean formula: combined mean = (66 × 20 + 70 × 15) / (20 + 15) = (1320 + 1050) / 35 = 2370 / 35 = 67.71%, which rounds to 67.7%. This accounts for the different sizes of the two sections.

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