A statistical test assesses the evidence provided by data against some claim (the null hypothesis H0). This applet allows you to gather data until you are ready to reach a conclusion about the truth of a null hypothesis. It illustrates the reasoning of tests: are the data compatible with a claim, or do they give evidence against it?
The basketball team at State Univeristy claims that each of their players makes 80% of his free throws. That's a null hypothesis. To test the claim for a player, ask him to shoot free throws by clicking Shoot. Click Show null hypothesis to display the percent he should make if the null hypothesis is true. You can get more data by clicking Shoot repeatedly. Do the data appear to agree with the 80% claim or to give evidence against it? When you are satisfied, click Show true % to see the truth for this player. Click New Shooter to test a different player, who may have a different free throw percent.