I have a survey that includes questions where you can choose one option from a list.
For example: "How often do you go to the supermarket?"
A. Every day B. 2-6 times per week C. Once per week or less D. Never
Say 1000 people respond to the survey and 100 people choose option A, 400 option B, 400 option C and 100 option D. How do you calculate the confidence intervals of these proportions? Are they simply binomial confidence intervals (i.e. just normal proportions)? Or is it something more complicated, because the proportions are related to each other?