Counting Possibilities
Averages are interesting, but many of the comparisons between customers involve counts, such as the number of customers who have responded to an offer, or who have stopped, or who prefer particular products. Counting is a simple process, and one that computers excel at.
Counting is not just about individuals, it is also about counting combinations. For instance, if there are ten teams in a baseball league, how many different possible games are there? Figure 3.6
The study of such combinations is called combinatorics, a field that straddles probability and statistics. The rest of the chapter looks at statistical approximations to questions about combinations, approximations that are good enough for everyday use.
This section starts with a small example that can easily be illustrated and counted by...