Wayne Gretzky was one of ice hockey’s most prolific scorers when he played for the Edmonton Oilers.

During his last season with the Oilers, Gretzky played in 41 games and missed 17 games due to injury. The article

“The Great Gretzky” (Chance [1991]: 16– 21) looked at the number of goals scored by the Oilers in games with and without Gretzky, as shown in the accompanying table. If we view the 41 games with Gretzky as a random sample of all Oiler games in which Gretzky played and the 17 games without Gretzky as a random sample of all Oiler games in which Gretzky did not play, is there evidence that the mean number of goals scored by the Oilers is higher for games in which Gretzky played? Use a .01.

n Sample Mean Sample sd Games with Gretzky 41 4.73 1.29 Games without Gretzky 17 3.88 1.18