Problema Solution
A student has earned scores of 87 , 81 , and 88 on the first 3 of 4 tests . If the student want an average ( arithmetic mean ) of exactly 87 , what score must she earn on the fourth feast ?
Answer provided by our tutors
Total score earned /number of tests = average score
therefore total score = 87 * 4 = 348
score of 4th test = 348- (sum of first threee tests)
= 348-(87+81+88)
=92