You cannot properly learn the methods of inferential statistics without first understanding the basics of probability. This chapter reviews the probability concepts necessary to understand the statistical methods discussed in this book. If you are already familiar with probability, you still should take the time to skim this chapter, if only to learn the vocabulary used to refer to probability concepts in subsequent chapters.
Events underlie all discussions about probability. Before you can define probability in statistical terms, you need to understand the meaning of an event.