7.5

K A poll asked residents of a certain country in 2016 and 2017 if they were happy. In 2016, 35% reported being happy and in 2017, 39% reported being happy Assume the sample size for each poll was 1000. A 95% confidence interval for the difference in these proportions , - P2 (where proportion 1 is the proportion happy in 2016 and proportion 2 is the proportion happy in 2017) is ( - 0.08, - 0.02). Interpret this confidence interval. Does the interval contain 0? What does this tell us about happiness among residents of this country in 2016 and 2017? The confidence interval 0, which tells us with V confidence that the proportion of people who reported being happy in 2016 was the proportion of people who reported being happy in 2017