Answer:
95
Step-by-step explanation:
The total of deviations from average must be zero.
<h3>deviations</h3>
(94 -90) = 4
(83 -90) = -7
(92 -90) = 2
(86 -90) = -4
and for the 5th exam:
(x -90) . . . . where the exam score is x
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<h3>total of deviations</h3>
We want the sum to be zero:
4 -7 +2 -4 +(x -90) = 0
x -95 = 0 . . . . . . . simplify
x = 95 . . . . . . . . . add 95
Candace must get a 95 or better to have an average of 90 for the 5 exams.
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<em>Additional comment</em>
When we're figuring this out mentally, we observe that 4 and -4 cancel, so Candace needs 5 more points than average to balance the net -5 she has from (-7+2). That is, she needs 90+5 = 95.
For many problems involving averages or sequences of numbers, it is often convenient to look at the deviations from average.