Suppose you ride to school with a friend and often arrive at a certain stoplight when it is red. One day she states, "It seems like this light is green only 10% of the time when we get here." You think it is more often than 10% and wants to test this. You keep track of the color (green/not green) the next 20 times you go to school and find that 4 times ( 4 / 20 = 20 % ) the light is green when you arrive. You wish to see if your sample provides strong evidence that the true proportion of times the light is green is greater than 10%. In other words, you are testing the hypothesis