Final answer:
The 95% confidence interval is (0.818, 0.862).
Step-by-step explanation:
To find the 95% confidence interval for the proportion of adults that support background checks for private and gun show sales, we use the provided survey result where 84% of the 2040 surveyed support these checks, with a margin of error of 2.2%.
The confidence interval is calculated by taking the sample proportion and adding and subtracting the margin of error.
Therefore, the confidence interval is:
(0.84 - 0.022, 0.84 + 0.022)
= (0.818, 0.862)
Interpreting this result means that we are 95% confident that the true proportion of all adults who support background checks for private and gun show sales lies between 81.8% and 86.2%.