Question

Homework Avg.: 88Quiz Avg.: 84Test Avg.: 78Final Exam: ??If the teachers weights Homework at 20%, Quizzes at 20%, Tests at 40%, and the Final Exam at 20%, what is the minimum grade Kevin can make on the final exam so that she scores a 80 in the class?

Answer 1

For this problem we know the following grades and the respective %

homework Avg: 88. 20%

Quiz Avg: 84. 20%

Test Avg: 40% 40%

Final Exam: X 20%

And we want to extimate the grade for the final exam in order to obtain an 80 for the class , so we can set up the following equation:

$(88\cdot0.2)+(84\cdot0.2)+(78\cdot0.4)+(X\cdot0.2)=80$

And we just need to find the solution for X, We can do some algebra first:

$17.6+16.8+31.2+0.2X=80$$0.2X=80-17.6-16.8-31.2$

And finally we can divide both sides by 0.2 and we got:

$X=\frac{14.4}{0.2}=72$

Then the final answer for this case would be an 80 to get a final grade of 80