Question

Your grades on your first three math tests were 81, 76, and 78. You have one more test to take. What grade do you need on that last test in order to get an 80 average? Write an equation and solve to determine your answer.

Answer 1

Equation: (81 + 76 + 78 + x) / 4 = 80

Solve: x = 83

You need to get an 83 on your last test in order to get an 80 average.