josephs final averages in science class are shown in the table below.

homework
% toward final grade-20%
average-93

quizzes
% toward final grade-20%
average-92

tests
% toward final grade-40%
average-85

final exam
% toward final grade-20%
average-?

what is the minimum score joseph can get on the final exam in order to receive at least 90 for his final grade?

2 answers

.2*93 + .2*92 + .4*85 + .2*X >= 90. Solve for X.
95