Solve the problem.
-A student earned grades of 84, 78, 84, and 72 on her four regular tests. She earned a grade of 78 on the final exam and 86 on her class projects. Her combined homework grade was 87. The four regular tests count for 40%
Of the final grade, the final exam counts for 30%, the project counts for 10%, and homework counts for 20%.
What is her weighted mean grade? Round to one decimal place.
A) 80.2
B) 81.3
C) 81.2
D) 82.1

Question

Quizplus · Accepted Answer

To calculate her weighted mean grade:
- Find the weighted average of her regular tests: ((84+78+84+72)/4) x 0.4 = 79.2
- Find the weighted average of her final exam: 78 x 0.3 = 23.4
- Find the weighted average of her project: 86 x 0.1 = 8.6
- Her homework grade is already weighted at 20%, so we don't need to do anything further with it: 87 x 0.2 = 17.4
- Add up the weighted averages for each component: 79.2 + 23.4 + 8.6 + 17.4 = 128.6
- Divide by the total weight (1, since we've already converted everything to percentages): 128.6/1 = 128.6
- Round to one decimal place: 81.2

Solve the Problem. -A Student Earned Grades of 84, 78, 84, and 72