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Given 4 scores of 81, 83, 87, 89:
what should be score number 5
in order to attain an average score of 88?
Average = | Sum of our 4 numbers + unknown score of x |
Total Numbers |
88 = | 81 + 83 + 87 + 89 + x |
5 |
81 + 83 + 87 + 89 + x = 88 x 5
x + 340 = 440
x + 340 - 340 = 440 - 340