Question

Alexis has the following grades in his math class: Homework grades: 80, 100, 90, Quiz grades: 84, 90, 72, Test grades: 64, 72. If the teacher weights Homework at 10%, Quizzes at 20%, Tests at 60%, what is her current class average? Be careful with this one, the categories do not sum to 100% because she has not taken her final exam yet.

70

74

78

82

Answer 1

74

Explanation:

Average is the sum of all the numbers divided by the number of numbers.

We will take average of Quizzes, Homeworks, and Tests. And multiply that by respective weights and find the weighted average of the 90%.

Quiz Avg:

(84+90+72)/3 = 82

Homework Avg:

(80 + 100 + 90)/3 = 90

Test Avg:

(64+72)/2 = 68

Now, weighted avg =
`(90(0.1)+82(0.2)+68(0.6))/(0.9)=73.55`

Rounding it off, we get "74", the correct answer.