ABSTRACT
It is rare to have data on every single member of a large group. In making a prediction concerning an upcoming election, polling firms work with a relatively small sample of the voting population, often less than 1,000. In determining unemployment rates or income levels, the Bureau of Labor Statistics works with only a sample of the population. The best ways of attaining a sample are described in Chapter 6. Here we discuss how to move from a small set of information to an estimate of what a truly complete survey would reveal. We are now at the heart of inferential statistics.
