Suppose you are testing the relationship between the size of a bowling ball, experience of the bowler, and number of pins knocked over. First, a professional bowls a 5 cm bowling ball and knocks over 1 pin, 3 pins, and 1 pin in 3 different trials. Then, an amateur bowls a 50 cm bowling ball and knocks over 10 pins, 10 pins, and 10 pins in 3 different trials. Thus you conclude that amateur bowlers knock over more pins than professional bowlers. What is wrong with this experiment and what can be done to correct it?