Entire Population: 30,000
Known properties of population: Age, gender, height, weight,
Ideal representative sample size: ???
This is for a mailing list test group selection.
Certain people can't be included in sample because they are on a do-not-mail list.
Sample group must have similar age, gender, height, and weight to entire population (known)
I imagine I have to randomly select members from the entire population that are not on the do-not-mail list and compare the average and variance of the sample compared to the entire population. If the average and variance of the sample and entire population are similar, then I have a good sample?
I'm not sure if I'm on the right path or if there is an easier way.