3
Bill is a huge Chicago Bulls fan and bought a 20-game ticket package to attend home Bulls games. Is he also a good
luck charm? In the 20 games he attended, the Bulls had 14 wins and only 6 losses, for a winning percentage of 70%. In
the remaining games that season, the Bulls had 27 wins and 35 losses, for a winning percentage of 44%. Even though
the p-value for a test comparing these percentages is very small, explain how confounding prevents us from
concluding that Bill is the cause of their increased ABILITY. Which of the following could be confounding variables to
this conclusion?