Calculating a GPA from numerous assignment and test grades

[PremedBeauty]

math problem:
pedro wants to calculate his gpa.
he has the lab grades:90/100,98/100,90/100,94/100,90/100,90/100,95/100,98/100. Labs are worth 20%.

He has the test grades: 9/10,6/10,10/10,10/10,5/10,7/10,7/10,7/10,10/10,10/10,8/10,10/10. Homework is worth 20%

test grades are: 35/100, 20/100, 26/100, 34/100. Exams are 40% (each exams are worth 10%).

What is his grades so far? What would his grade be is he had a 90 on the final which is worth 20%?

I got 62 for his current grade but I am not sure

 

[HallsofIvy]

Assuming that each lab counts equally toward his "lab grade", add them all together and divide by 8.
Find his "homework" grade by adding them all together and dividing by 12.

You can either treat each test separately or all together by adding the test scores and dividing by 4.

Since you do not yet have a final exam grade, you can find his "current grade" in either of two (equivalent) ways:
The lab, homework, and tests are "weighted" 20, 20, 40: that's the same "ratio" as 1, 1, 2. Add lab grade+ homework grade+ 2*test grade and divide by 1+1+2= 4.
Or multiply lab grade by .20, homework grade by .20, test grade by .4, add them together and divide by .20+ .20+ .40= .80. You should get exactly the same answer either way. I get 73% for his "current grade".

If he gets 90% on the final exam (he got 35, 20, 26, and 34 on the regular tests and you expect him to get 90 on the final exam??). Then his grade would be .2*lab grade+ .2*homework grade+ .4*test grade+ .2*final exam.
Since .20+ .20+ .40+ .20= 1.00, you don't need to divide by anything. I get 76% for his final grade.

 

[PremedBeauty]

One more question: does it matter if you multiply each test grade by .10 (since they are 10% each) then divide by?

for exams total:115/400*.2=11.5/40 *100=28.75
labs total: 745/800*.2=149/19.8*100=93.125
homework:99/12*.2=19.8/24=83.5
add them up and divide by .8?