Major League Baseball (MLB) includes two groups of teams, in two ?leagues.? There are 15 teams in each of the American League (AL) and the National League (NL). Since 1997, teams in each of the leagues play teams from the other league in ?interleague? regular-season games. One way to determine whether one league is stronger than the other is to consider the interleague winning percentages for all the teams in one of the two leagues, say, the National League, for one season. For purposes of this exercise, consider the interleague games played in the 2016 season to be a representative sample of the performance of the teams in a population of potential future seasons. Here are the 2016 interleague winning percentages for the 15 NL teams:

a. What characteristic of this sample of NL team interleague winning percentages indicates that the methods based on the t distribution may not be appropriate?

b. Use a randomization test (Shiny app: ?Randomization Test for One Mean?) to perform a test of the hypothesis that the population mean interleague winning percentage for NL teams differs from 50%.

c. Use the results from Part (b) to explain whether it is reasonable to say that the National League or the American League performs significantly better than the other in interleague play.

Transcribed Image Text:

Winning Percentage Team ARI 5 15 25% ATL 8. 12 40% CHC 15 5 75% CIN 5 15 25% COL 11 45% LAD 10 10 50% MIA 14 30% MIL 11 55% NYM 12 8 60% PHI 11 55% PIT 9. 11 45% SD 6. 14 30% SF 8. 12 40% STL 8. 12 40% WSH 12 8. 60%