Which comedy duo performed the famous baseball routine "Who's on First?"

Which song is traditionally sung during the seventh-inning stretch? At which ballpark do fans sing "Sweet Caroline" in the eighth inning? Which Cubs broadcaster was famous for leading the crowd in "Take Me Out to the Ball Game"? Which broadcaster called Dodgers games for 67 seasons? Which Brewers broadcaster and actor was known as "Mr. Baseball"? Which 1989 film features the line "If you build it, he will come"? Which film tells the story of the Oakland A's use of statistics under general manager Billy Beane? Which 2013 film tells the story of Jackie Robinson?