>Wouldn’t the desired sample size depend on the size of the population itself? No, The most important thing is the distribution of the sample size. You have to

>Wouldn’t the desired sample size depend on the size of the population itself? No, The most important thing is the distribution of the sample size. You have to make sure it isn't obviously biased in some way (i.e You're only surveying students in a university for extrapolation on the entire population of the country). Beyond that, the desired sample size levels off quickly. 5000 (assuming the same distribution) won't be any more or less accurate for 10M than it is for 1M. Of course, if you just ask everyone or almost everyone then you no longer need to worry about distribution but yeah