Weights:
Homework - .4 (score) - (.4)(.95) = .38
Quizzes - .25 (score) - (.25)(.84) = .21
Final Exam - .35 (score) - (.35)(x)
Adding the results up, we get 0.59 + 0.35x
We need to set it up to .87.
0.59 + 0.35x = 0.87
0.59 - 0.59 + 0.35x = 0.87 - 0.59
0.35x = 0.28
x = 0.28/0.35 = .8
Multiplying by 100, he needs an 80% on his final to get an 87% overall
Percentage = dividing by 100.
the desired addition result is 0.87