Question

A friend has a 84% average before the final exam for a course. That score includes everything but the final, which counts for 25% of the course grade.

What is the best course grade your friend can earn?
%

What is the minimum score would your friend would need on the final to earn a 75% for the course?
%

Give answers accurate to at least one decimal place.

Answer 1

Best score
75% of his grade is an 84%
25% of his grade is a 100% (final)
.75(.84) + .25(1) = .88 or 88%

Minimum score
.75 = .75(.84) + .25x
.75 = .63 + .25x
.12 = .25x
x = .48 or 48%