Question

If category A is 10%, Category B is 10%, Category C is 35%, and Category D is 10% of John's grade and his grades are as follows: Cat. A: 0, 99, 86, 87 Cat B:100, 96, 96 Cat C: 91 and Cat D: 94. What is John's grade?

Answer 1

add all the grades in cat A and then find 10% of it
similarly do with cat B, cat C and cat D
then add the results from above to get the final answer

Answer 2

I got a 114.95 and I don't think that's right...

Answer 3

After adding all the grades within each category, you also divide by the # of grades

Answer 4

You have only defined 10% + 10% + 35% + 10% of the total grade
what accounts for the rest of it?

Answer 5

what do you mean?

Answer 6

So after adding all the grades in category A,
divide by the number of grades... how many are there?

Answer 7

Cat. A is supposed to be 20%. sorry. and there are 4 grades

Answer 8

you mean to take avg then take 10% of the cat A? @Miracrown

Answer 9

can you repeat the weighting of the categories again?
because I still don't think it adds up to 100%

but if the grades within A are 0, 99, 86, 87
then the average is (0+99+86+87)/4 or 68

Answer 10

Cat A is 20%, Cat B is 10, Cat C is 35, Cat D is 10. Cat E is 25 but there is no grade in that category

Answer 11

there is no grade in that category? what do you mean

Answer 12

is it just zero?

Answer 13

Part A is calculating his current grade, Part B is determining what he needs to make on his final to get and A, B, and C in the class.

Answer 14

Oh, I see. So that final exam goes into category E?

Answer 15

Correct

Answer 16

Yes so let's continue doing the averages, we have:
Category A, we have 0.2*(0+99+86+87)/4

For Category B, we have 0.1*(100+96+96)/3

Category C will contribute 0.35*91 and Category D contributes 0.1*94

What does all that add up to?

Answer 17

64.55

Answer 18

Yes, but here's the thing ... only 75% of the grade has been accounted for, right?

Answer 19

correct

Answer 20

so we divide that by 0.75
What do you get?

Answer 21

86.06

Answer 22

86.1 yes

Answer 23

so that's the grade right now, does tat make sense now?

Answer 24

Yes, thank-you so much!

Answer 25

Yw, and for the rest of the parts you basically do the same thing, except the grade after the final exam will be 0.75*86.1 plus 0.25*final exam grade.

So if the final exam grade is a variable, call it "x"
then you can write an equation to solve for x
by saying 0.75*86.1 + 0.25*x = (Grade you want to get in the class)

Answer 26

Why do you do the +0.25?

Answer 27

because the grade on the final exam is weighted at 25%

Answer 28

Oh, duh. That makes sense. Thank-you!

Answer 29

I'm glad :)