Question

On his first 5 English tests, Jeff received the following scores: 70, 72, 75, 65 and 74. What test score must Jeff earn on his sixth test so that his average (mean score) for all six tests will be 70?

Answer 1

Answer:

Since the student's average test score on 4 tests is 78, then the sum of the first 4 test scores is 4*78=312. We need the sum of ALL 5 scores to be 5*80=400, so if is the 5th test score, then -->