To pass a course with a B grade, a student must have an average of 80 or greater. A student’s grades on three tests are 73, 86, and 78. Find what score the student must get on the next test to get a B average or better. What grade must the student get? ___ or greater.

Guest Feb 18, 2021

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*To pass a course with a B grade, a student must have an average of 80 or greater. A student’s grades on three tests are 73, 86, and 78. Find what score the student must get on the next test to get a B average or better. What grade must the student get? ___ or greater.*

Call the required minimum grade on the next test **x**

After having taken the next test, i.e., the fourth test, the student wants an average of 80.

the scores he has made ..... 73 + 86 + 78 + **x**

divided by .... ———————— equals 80

the total number of tests ..... 4

this relationship is **x** + 237 / 4 = 80

multiply both sides by 4 **x** + 237 = 320

subtract 237 from both sides **x** = 83

The student must score **83** on the fourth test to have an average of 80.

_{.}

Guest Feb 18, 2021