7 * 80 = 560
He needs a total of 560.
6 * 78 = 468
He has a total of 468.
560 - 468 = ______ score he needs on next test.
After his first six biology tests, Ruben has a mean score of 78.What score does Ruben need on the next test to raise his average (mean) to 80?
1 answer