Question: The last closely contested presidential election pitted John McCain against Barack Obama in

2008. A poll taken immediately before the 2008 election showed 51% of the sample intended to vote for Obama. The polling organization announced that they were 95% confident that the sample result was within 2% points of the true proportion of all voters who favored Obama.

a) Explain in plain language to someone who knows no statistics what “95%

confidence” means in the announcement.

b) The poll showed Obama leading. Yet the polling organization said the election was too close to call. Explain why.