Roberto is a fan of the Los Angeles Angels baseball team. Since he works at night he only

goes to day games. Last year he attended all 16 home day games and saw his team win 11

and lose only 5 games, for a winning percentage of 68.8%. In their other games the team won

69 and lost 77, for a winning percentage of 47.3%.

Even though the p-value for a test

comparing these winning percentages is very small, explain how confounding prevents us

from concluding that Roberto’s attendance at those games is the cause of the Angels success

in those games.

There are other factors than Roberto coming that could have affected the outcome of the game. For example, maybe the night games were against better teams to generate better ratings in prime time. Moreover, maybe the Angels do better at home due to home-field advantage. There are many factors such as these that could explain why Roberto witnessed such a high win rate at the games he went to, so it cannot be concluded that Roberto's attendance caused the Angels to win.