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
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
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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