In a poll taken in December 2012, Gallup asked 1006 national adults whether they were baseball fans, 47.6% said they were. Almost fiver years earlier, in February 2008, only 34.8% of a similar-size sample had reported being baseball fans.

a) Find the margin of error for the 2012 poll if we want 90% confidence in our estimate of the percent of U.S. adults who are baseball fans.