## ABSTRACT

In the previous chapters, we studied ways in which descriptive statistics can be used to organize and summarize a set of data. However, in addition to describing a group of observations, we might also be interested in investigating how the information contained in the sample can be used to infer the characteristics of the population from which it was drawn. Before we can do this, we must first lay the groundwork. The foundation for statistical inference is the theory of probability. In Chapter 5, we used the term probability as a synonym for proportion. Before we can give a more precise definition, we must first explain the concept of an event.