Confidence intervals aren't difficult. Since you have a proportion, Just use the formula . This is the margin of error.And, confidence intervals are very hard. Can someone break how to do a 95% interval down. Say 1000 people were interviewed about smoking and 600 said they did. How would you do that interval? Can do you do it on a calculator?
p=0.60, q=1-p, n=1000. z that corresponds to 95% CI is 1.96
So, you can say with 95% confidence that the proportion of people who say they smoke is between 56.96% and 63.04%.