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.