I don't remember what the graph is called but, for every dot on top of the number on the number line, is one player. Sounds weird, I know.
For example, the number 77. You see how there are 3 dots on top of 77? That means 3 players are 77 inches. When there are no dots, for example 73 inches, that means 0 players are 73 inches.
So, how many players are 78 inches tall?