In Chapter 1 we discussed graphical and numerical summaries for a single variable. We continued these ideas in studying the relationship between two variables in Chapter 2. Then in Chapter 3, we explored sources of data and the need for carefully collected data. The leap from data to conclusions is based on statistical inference, which is is expressed in terms of probability, the subject of this chapter.

The methods we will discuss in this chapter will help us to answer questions such as

• What is the chance of being dealt two aces in a hand of Texas hold’em?
• If I play the lottery many times, how much will I win or lose in the long term?
• Is there a “hot hand” in basketball?