Question

Stu dent received scores of 87 and 91 on his first two exams of the grading period. What is the lowest score Stu must earn on the next exam for the test average to be at least 90 for the grading period.

Answer 1

90 x 3 = 270

270-(87+91) = x

270-178=92

x=92

87+91+92 =270

270/3 = 90

 he needs at least a 92 

Answer 2

The lowest score the student must earn on the next exam for the test average to be at least 90 for the grading period is 92

How to determine the lowest score?

The two scores are given as:

87 and 91

The average score is at least 90

Let the third score be x.

So, we have:

Average = Sum/Count

This gives

(x + 87 + 91)/3 = 90

Evaluate the sum

(x + 178)/3 = 90

Multiply through by 3

x + 178 = 270

Solve for x

x = 92

Hence, the lowest score is 92

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