I need help finding this inequality to calculate need points to earn my goal grade. Will someone please help!?

Question

We have had 4 exams so far. we have 3 left including the final as two of the three. each exam was worth 125 pts the final is 250. On the 4 exams I recieved: 82%,82%, 60%, and 78%. How do I plug in these numbers into an inequality to find the minimum number of points needed on the subsequent exams for an A, B, C, D?

Answer 1

Sure. First of all, roll up the individual grades into one general figure: the points you have so far. Take each of the four percentages, multiply by 125, and then add the four point scores together. That's how many points you've scored so far out of 125*4 = 500.
You have one exam plus the final remaining, for a total of 875 points.
How many points out of 875 do you need for an A? You didn't specify the grading scale in your question -- it varies from school to school, and often from class to class. I've taught classes with the A cutoff being 93%, 90%, and some as low as the mid-80s.

For illustration, let's assume that the A cutoff is 90%. You need to score enough points on the remaining exams such that the total is at least 90% of 875:

125*(0.82 + 0.82 + 0.60 + 0.78) + x >= 0.90 * (5*125 + 250).

You need a series of inequalities, one for each grade level. You'll probably want to do the multiplications to simplify the equation, too. Finally, you solve each one for x, to find out what minimum scores you need.

Answer 2

You have had 500 points possible and have made 377.5 of them or 75.5%.

If 90 is an A, 80 is a B, 70 is a C, and 60 is a D, then
you would need
x + 377.5 >/= 900 to get an A
x >/= 522.5 to get an A, therefore it is impossible

x + 377.5 >/= 800 to get a B
x >/= 422.5 to get a B, that's 84.5%, doable if you work

x + 377.5 >/= 700 to get a C
x >/= 322.5 to get a C, that's 64.5% - simple

Answer 3

D= / >612/875
C= / >638/875
B= / >700/875
A= / >787/875