SOLUTION: If 85% of the years tests are over and my average is 63%, and my end of year exam is worth 15% of my grade, what score do I need to keep my average at 63%

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Question 816673: If 85% of the years tests are over and my average is 63%, and my end of year exam is worth 15% of my grade, what score do I need to keep my average at 63%
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
the formula is:
.85 * 63% + .15 * x = 63%
solve for x to get:
x = (63% - .85*63%) / .15 which results in:
x = 63%

if you want to raise your score to 65%, then the formula would be:
.85 * 63% + .15 * x = 65%
solve for x to get:
x = (65% - .85 * 63%) / .15 which results in:
x = 76.333333333%


the best you can do is if you get 100% on the final.
then your overall average would be:
.85 * 63% + .15 * 100% = 68.55%