Modern tennis rackets are mostly made of graphite while older rackets were made of wood. A study claimed that the stiffness of modern tennis rackets has led to a greater incidence of tennis elbow. Match each general term to the matching specific item from the study. 1. independent variable 1 the stiffness of a tennis racket 2. dependent variable 2 the occurrence of tennis elbow 3. type of study 3 inferential