Question

A student’s final grade in chemistry is determined by the following weights:
Quizzes 5%
Exam 1 20%
Exam 2 20%
Lab Reports 15%
Research Paper 15%
Final Exam 25%

The student received the following grades:

Lab reports: 75 80 70 75 85 69 90 75
Quizzes: 85 60 70 0 75 80 80 80
Exam 1: 80
Exam 2: 70
Research Paper: 85
Final Exam: 75

What is the final grade for this student?


The answer I got was 75.95 and it came out to be wrong. To get this answer I added each one category at a time and then divided it by the appropriate percentage. I do not know what I am doing wrong. Please help me.

Answer 1

multiply each average score by its weight, and add them up.

quizzes: 66.25
Labs: 77.375

Now weight the scores as indicated:

0.05*66.25 + 0.20*80 + 0.20*70 + 0.15*77.375 + 0.15*85 + 0.25 * 75 = 76.42

You do it this way because if all the weights (percentages) add up to 1, then those portions of a perfect score (100) will add up to the total.

If all the scores are 100, then since all the weights add up to 1, the final grade is also 100.