A physicist, engineer and a statistician are out hunting. Suddenly, a deer appears 50 yards away.
The physicist does some basic ballistic calculations, assuming a vacuum, lifts his rifle to a specific angle, and shoots. The bullet lands 5 yards short.
The engineer adds a fudge factor for air resistance, lifts his rifle slightly higher, and shoots. The bullet lands 5 yards long.
The statistician yells "We got him!"