Answer:
99% Confidence interval: (0.21,0.27)
Step-by-step explanation:
We are given the following in the question:
Sample size, n = 1370
Proportion of adults who rated economy as good =
[tex]\hat{p} = 24\% = 0.24[/tex]
99% Confidence interval:
[tex]\hat{p}\pm z_{stat}\sqrt{\dfrac{\hat{p}(1-\hat{p})}{n}}[/tex]
[tex]z_{critical}\text{ at}~\alpha_{0.01} = \pm 2.58[/tex]
Putting the values, we get:
[tex]=0.24\pm 2.58(\sqrt{\dfrac{0.24(1-0.24)}{1370}}) = 0.24\pm 0.0297\\\\=(0.2103,0.2697)\\\approx (0.21,0.27)[/tex]