The chemist says, "No! No! I know what to do! We must cut off the supply of oxygen so that the fire will go out due to lack of one of the reactants."
As the physicist and the chemist debate what to do, the statistician actually does something. He runs around the room lighting more fires. The physicist and the chemist scream "What are you doing?"
The statistician replies, "We're going to need a larger sample size."