Question

ok, i need help.

lets say my grade is 86%.. Now, how many points would i need in order to raise it to an 89 or 90%? The test i want to correct has 12/16 points, or 75% of the test. That test is worth 21% of my grade. my Final test is worth 25%. If i do corrections on the test with 75%, and i correct all the answers (correcting an answer only gives 1/2 of a point, so 0.5) AND i get all answers correct on that final test, what would my grade be?

what would my grade be if i got all test corrections RIGHT but i DIDN'T do final test yet?

Answer 1

I'll show the steps and assumptions I used, then give the answers.

Assumptions
- Weights: test = 21%, final = 25%, everything else = 54% (these sum to 100%).
- Your current 86% is the course grade so far (i.e., based on the completed work: the 21% test + the 54% other work). The final isn't graded yet.
- Your test was 12/16 = 75%. You can earn +0.5 point per corrected wrong answer; you had 4 wrong, so max +2 points → 14/16 = 87.5%.

Step 1 — find your "other work" average
Let O = average on the other work. Current grade 86% is the weighted average of test and other, normalized over completed weight (0.21+0.54=0.75):

(0.21*0.75 + 0.54*O) / 0.75 = 0.86
→ 0.21*0.75 + 0.54*O = 0.645
→ 0.1575 + 0.54*O = 0.645
→ O = 0.902777... ≈ 90.28%

Step 2 — your corrected test score
12/16 → +2 points → 14/16 = 0.875 = 87.5%.

Scenario A — you do all corrections (test = 87.5%) AND get 100% on the final
Final course grade = 0.21*(0.875) + 0.54*(0.90278) + 0.25*(1.00)
= 0.18375 + 0.4875 + 0.25
= 0.92125 ≈ 92.13%

So you'd end up about 92.1%.

Scenario B — you get all test corrections right but haven’t taken the final yet
Your current course grade (based on completed work only) becomes:
(0.21*0.875 + 0.54*0.90278) / 0.75 = 0.67125 / 0.75 = 0.895 = 89.5%

So after corrections (before final) your displayed/current grade would be about 89.5%.

Extra useful numbers
- With the corrections done (test = 87.5%), the final percentage you need to reach a 90.0% overall:
Solve 0.67125 + 0.25*f = 0.90 → f = (0.90 − 0.67125)/0.25 = 0.915 → 91.5% on the final.
- Without doing corrections (test stays 75%), getting to 90% overall is not possible (you’d need >100% on the final). To hit 89% without corrections you'd need about 98% on the final.

If you want, I can recalc under different assumptions (for example if your 86% already includes a placeholder for the final or if the teacher counts current grade differently).