Ok well I have this basic problem in which there are grades (4 grades). There's an upcoming final that is weighted to be some fraction toward the final grade (2/3). I have to find what the final grade has to be to get an average grade of 80. and then 90. I completly forgot the procedure as to how to tackle this problem. Anybody have any hints/tricks for me to start me off?
Computing Grades-getting average from a weighted test
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0@Deven Ware: You can't edit comments after a little while. I think you can edit your own answers any time. – 2011-09-13
1 Answers
The key to solving this problem is to realize that there are essentially two components that will go into the final grade :
1) The average of the previous four tests
2) The grade on the final
Thus we can set it up as follows : Let $G =$ Grade in the class, $a =$ average score from the previous 4 tests, and $f =$ final exam score. \begin{align*} G = \frac{2f}{3} + \frac{a}{3} \end{align*}
Using you're numbers you can solve for whatever possibilities you need.
EDIT: you can also use this approach for any different weightings by simply changing the fractional amounts that $a$ and $f$ are worth, for example if you want the final $f$, to be worth $3/4$ the final grade then it would reflect as: \begin{align*} G = \frac{3f}{4} + \frac{a}{4} \end{align*}
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0Awesome, i shall $f$orever remember this for future upcoming questions similar to this one. – 2011-09-13