A Gallup poll asked college students in 2016 and again in 2017 whether they believed the First Amendment guarantee of freedom of the press was secure or threatened in the country today. In 2016, 2489 out of 3072 students surveyed said that freedom of the press was secure or very secure. In 2017, 1808 out of 2014 students surveyed felt this way.

a. Determine whether the proportion of college students who believe that freedom of the press is secure or very secure in the country changed from 2016. Use a significance level of 0.05.

b. Use the sample data to construct a 95% confidence interval for the difference in the proportions of college students in 2016 and 2017 who felt freedom of the press was secure or very secure. How does your confidence interval support your hypothesis test conclusion?