An employment agency requires applicants average at least 70% on a battery of four job skills tests. If an applicant scored 70%, 79%, and 89% on the first three exams, what must he score on the fourth test to maintain a 70% or better average?
If the average of 4 numbers is 70, then their sum is 280. If three of the numbers add up to 238, then the missing number is (280 - 238) = 42. This applicant should have no problem.
