At a certain high school, the respective weights for the following subjects are Mathematics 3, English 3, History 2, Science 2 and Art 1. What is a student’s average whose marks were the following: Geometry 89, American Literature 92, American History 94, Biology 81, and Sculpture 85?
85.7
87.8
88.9
89.4
90.2
I KEEP getting the wrong answer. I know what the right answer is, I just cant figure out the formula. Can anyone please explain the formula? And plz dont answer with IDK, just for the points. TY
2007-04-02 10:19:40 · 4 answers · asked by Hailey B 1 in Science & Mathematics ➔ Mathematics
Take the weight times the average for each class...
Geometry: 3 * 89 = 267
Am Lit: 3 * 92 = 276
Am Hist: 2 * 94 = 188
Biology: 2 * 81 = 162
Sculpture: 1 * 85 = 85
Add those:
267 + 276 + 188 + 162 + 85 = 978
Now add the weights for each class:
3 + 3 + 2 + 2 + 1 = 11
Divide 978 / 11 = 88.9
2007-04-02 10:27:22 · answer #1 · answered by Mathematica 7 · 0⤊ 0⤋
Average =(3*89+2*94+2*81+1*85 +3*92)/11=88.9
Multiply the points of each subject by the weight.
Sum up and divide the sum by the sum of the weights
2007-04-02 17:36:16 · answer #2 · answered by santmann2002 7 · 0⤊ 0⤋
This is known as a "weighted average":
Multiply each by the given weight, total these answers up, then divide by the total of the weights.
Total of weights times grades:
3*(89) + 3*(92) + 2*(94) + 2*(81) + 1*(85) = use calc.
Total of weights:
3+3+2+2+1 = 11
Divide your answer to the first computation by 11 to get the weighted average.
2007-04-02 17:26:39 · answer #3 · answered by tedfischer17 3 · 0⤊ 0⤋
You must add them all up, then divide by the number of subjects the student took.
89+92+94+81+85=441
441 divided by 5 (Geometry, Literature, History, Biology, Sculpture)= 88.20
Hmm, I don't know why it is not on your list. 88.20 is the MEDIAN average.
2007-04-02 17:29:25 · answer #4 · answered by Anonymous · 0⤊ 1⤋