“If there are any PhD statisticians out there, they can do the calculation. It is computer driven but I do not have the program or the knowledge to do the math. It is very easy to do though if you are trained.”
You don’t need a statistician for this. The problem is called “extrapolating from a non-representative sample”. If you survey a bunch of convicted felons and find that 30% have stabbed people, it’s not valid to conclude that 30% of US males have stabbed someone.
Agreed and point well made. What I wanted to know was how large a sammple would be needed to give assurance of legitimacy. In addition, as was pointed out, one needs to define demographic groups and do a multivaritae analysis. What I mean here is to put all the information “in the pot” so to speak and see what matters. For example, if one studies any observation and compares it with one element of a demographic group, the answer may not be correct. For example, if one studies an event related to “maleness”, you need also to include all (or as many as possible) of the variables that maleness entails. Examples would be age, weight, race, conditioning etc. One may find out that an observation associated with maleness is really associated with age. Am I being clear? Sometimes I am not as clear as I would want to be.