A political candidate feels that she performed particularly well in the most recent debate against her opponent. Her campaign manager polled a random sample of 400 likely voters before the debate and a random sample of 500 likely
voters after the debate. The 95% confidence interval for the true difference (post-debate minus pre-debate) in
proportions of likely voters who would vote for this candidate was (-0.014, 0.064). What is the correct interpretation of
the 95 percent confidence interval?
o Only 95% of the voters who were polled responder to the question.
The candidate can be 95% confident that the percentage of likely voters who would vote for her increased, since
much of the confidence interval is above 0.
The candidate can be 95% confident that the percentage of flikely voters who would vote for her did not increase,
Since the confidence interval contains 0.
We are 95% confident that the interval from -0.014 to 0.064 captures the true change in the proportion of likely voters
who would vote for this candidate.