# math average!

posted by on .

My average is a 74 right now. My grades are
70( which counts as 60% as my grade and i have 2 more major test coming up)
94, 60 (which counts as 25% and i have about 5 more of this coming up)
90,100,83,91,71( i have about 3 more of these and they count as 15%)
This was an extension to my last question. I know this is a lot but what grades what i need to get in order to get an 85?

• math average! - ,

If you get an average of a,b,c from now on for the 3 sections, respectively, you want the weighted sum to be 85 points:

.6(70+2a)/3+.25(94+60+5b)/7+.15(90+100+83+91+71+3c)/8 = 85

0.4a + 0.1785b + 0.05625c + 27.6563 = 85
0.40a + 0.18b + 0.06c = 57.35

If you got 90% on everything from now on, that would give you an extra

.4*90 + .18*90 + .06*90
= 36+16.2+.54=52.74 points, which would still fall short of the goal.

Play around with a,b,c to see how you have to perform on the rest of the tests. Good luck. You have made some good scores, so you know it can be done, but it's be hard going.