What is a simple formula for doing this (determining the best sample size) for each population?
This is the formula for calculating a confidence interval for proportions. If you are using something and you only decide whether the grave sites meet your criteria or they do not then your test is for proportions, rather than means. This means that rather than assigning each item a number you are merely testing what proportions of the populations is yes. I am assuming that this is what you are doing based on your answer to my clarification question. How you solve for the sample size of an eighty percent confidence interval is as follows. First, I will show you how to solve assuming that your prediction is accurate. First you have to decide on a margin of error that you are willing to have. The margin of error is what will bound the percentage that you get. So how large you are willing to allow your confidence interval to be before you decide that it is no longer useful. You must choose some margin of error. I will do the example with a margin of error of 3% because that is fairly stan
