Probability Workbook For Dummies

Chapter 2

Teaming up with Probability Terms and Rules

IN THIS CHAPTER

Setting up your set notation

Discerning different types of probabilities and rules that go with them

Recognizing when events are independent and when they are disjoint

Probability comes with its own language, symbols, and rules, and in this chapter, you review the basics of all of those things. First, you start building up set notation, then you apply the notation to various types of probabilities, such as marginal, joint, and conditional probabilities. Then you apply rules to these probabilities to be able to calculate more complex probabilities. At the end, you find out how you know whether two events — like a playing card being a diamond and red — are independent. (In case you’re wondering about the playing card, no, they are not independent!)

Building up Your Set Notation

It all starts with some random phenomena: You pull a card from a 52-card deck, you roll a die, you flip a coin. And you have the set of all possible outcomes denoted by S, the sample space. For example, if you flip a coin twice, your sample space is . Then you have events such as A, B, or C that are subsets of S. For example, ; B might ...