As of 2011, Division I college football in the US does not have a tournament-style playoff to pick a national champion. In a random survey conducted by Quinnipiac University, people who identified themselves as college football fans were asked if they favor a playoff system, similar to college basketball, to determine a national champion. Of those sampled, 63% said they would favor such a system, and the margin of error is ±3.1%. Assuming the margin of error corresponds to a 95% confidence interval, about how many college football fans were sampled?