Keith has scored 21, 30, 27, 26, and 19 points in his five basketball games so far. how many points does he need to score in his next game so that his average (mean) is 25 points per game?

First thing you're gonna have to do is write an equation to represent this. Remember that an average is all the numbers added together, divided by the number of numbers. Let x represent the points Keith needs to score in his next game. He's already played 5 games, so including the next game, he will have played 6. Here's the equation:

25=(21+30+27+26+19+x)/6

25=(123+x)/6

25(6)=123+x

150=123+x

27=x

Keith needs to score 27 points in his next game to have an average of 25 points per game.