Multiply the average by the number of tests to find the total of the scores:
82 x 3 = 246
88 x 3 = 264
The total of the three tests would need to be between 246 and 264
The total of the first two tests is 79 + 85 = 164
Subtract the total of the first two from the totals above:
246 - 164 = 82
264 - 164 = 100
The score of the third test needs to be between 82 and 100
