Question

Suppose that you are taking a course that has 4 tests. The first three tests are each worth 20% of your final grade, and the fourth test is worth 40% of the final grade. To get a B in the course, you must have an average of at least 80 percent on the 4 tests. Your scores on the first 3 tests were 63.5 %, 76 %, and 87 %. What is the minimum score you need on the fourth test to get a B for the course?. Don't round your answer.​

Answer 1

86.75

Explanation:

Given test scores of 63.5, 76, and 87 that each count for 20% of your grade, you want to know the fourth test score needed for an average of 80, if the fourth test is worth 40% of your grade.

Course grade

The grade for the course, with fourth test score x, will be ...

0.20(63.5 +76 +87) +0.40x = 80

0.40x +45.3 = 80

Solving for x, we get ...

0.40x = 34.7 . . . . subtract 45.3

x = 86.75 . . . . . . . divide by 0.4

The minimum score you need on the fourth test is 86.75.

<95141404393>