Posted by rowlo on Thursday, June 23, 2011 at 12:26pm.
Jacob has a mean score of 78 after his first four math tests. He wants to make a B, or an average of 80, in math. What does he need to score on the fifth test to have a mean score of 80?

algebra  Ms. Sue, Thursday, June 23, 2011 at 12:30pm
80 * 5 = 400
78 * 4 = 312
400  312 = 88