A tennis player keeps track of the number of balls he hits out of the court each game for four games. Here are his numbers: Game 1 15 balls out of the court, Game 2 = 21 balls out of the court, Game 3 = 5 balls out of the court, Game 4 = 51 balls out of the court. What is the average number of balls that he hits out of the court each game? 23 21 92 4