Stephen earned scores of 88 points, 94 points, 89 points, and 85 points on four tests. What is the lowest score he can get on the fifth test and still finish with an average score of 90 points? 94 points
95 points
96 points
97 points

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Explanation:

The lowest score Stephen can get on the fifth test is 94 points.  

This is how,

Test 1 = 88 points

Test 2 = 94 points

Test 3 = 89 points

Test 4 = 85 points

Let the marks scored by Stephen on the fifth test be x points.

Now, The average score in all the tests = 90 points

Sum of all the five tests added together = 88 + 94 + 89 + 85 + x

= 356 + x

Continuing, the average × 5 = Sum of five tests

90 × 5 = 356 + x

450 - 356 = x

x = 94

Therefore, the lowest score Stephen can score on the fifth test is 94 points.