Chapter 11
Two-Way Tables
IN THIS CHAPTER
Organizing probabilities in two-way tables
Figuring marginal, conditional, and joint probabilities
Checking for independence
Categorical variables place individuals into groups based on certain possible outcomes. For example, gender (male, female) whether you ate breakfast this morning (yes, no), or political affiliation (Democrat, Republican, Independent, Other). Oftentimes you look for relationships between two categorical variables; for example, “Are females more likely to eat breakfast than males?” A two-way table classifies individuals into groups based on all possible pairs of outcomes of two categorical variables (for example, male breakfast eaters, female breakfast eaters, and so on). In this chapter, you see how two-way tables help you organize and figure probabilities and check for independence of two events.
Organizing and Interpreting a Two-Way Table
Suppose you are a basketball nut and you love to watch your favorite player shoot free throws. After watching him shoot pairs of free throws for a long time, you notice two things. First, it seems like he makes the second shot more often than he makes the first. You also believe, ...