Math Question..?

Question

I had a 96.6% in my biology class, and i took a test which i got an 85% on. After this 85% my grade dropped to an 89.8%. How much percent of my total grade would the test have to be for my grade to drop 7%!?

Also, does anyone else think this is completely ridiculous??

Answer 1

x = the weight grading % that's applied to test score

96.6 - 85x = 89.8

85x = 6.8

x = 0.08 = 8%

Now that I look at it, a 7% drop because of one exam does seem a bit harsh in light of your high starting average. If you still have your class syllabus, check it to see how previous and future exams are weighted. Even if your teacher is Satan in human form, you still should have options to earn extra credit in some way. Good luck.

Answer 2

Let x = weight of the grade

96.6(1 - x) + 85x = 89.8
96.6 - 96.6x + 85x = 89.8
11.6x = 6.8
x = 17/29 or 59 18/29%

Answer: the weight must be 17/29 or 59 18/29%. I can't say if this is completely ridiculous because I don't know the policy of school's grading system. If this violates or doesn't comply with the school's policy then I would say it's completely ridiculous and you need to seek for redress regarding your grievance.

Proof (The result would be 89.8%):
= (96.6% * [1 - 17/29]) + (85% * 17/29)
= (96.6% * 12/29) + 49 24/29%
= 39 141/145% + 49 24/29%
= 39 141/145% + 49 120/145%
= 88 9/5% or 89 4/5% or 89.8%