Chapter 3: Numerically Summarizing Data

Let's again review the process of statistics we introduced in Section 1.1:

In Chapter 1, we focused on how to collect data. In Chapter 2, we talked about how to organize and summarize data using tables in graphs. In this chapter, we'll introduce various ways to summarize data numerically, along with one new graphical representation - the box plot. In general, we have three ways to summarize the distribution of a random variable - shape, center, and spread. Shape was discussed back in Section 2.2, but the center and spread will be introduced here in Section 3.1 and Section 3.2, respectively. Section 3.3 talks about estimating measures of center and spread from grouped data.

In Section 3.4, we talk about summarizing information about an individual observation in relation to the rest of the sample/population. (We call these measures of position.)

And finally, in Section 3.5, we introduce a new graphical representation of data called the box plot. We'll be using this plot frequently throughout the semester.

If you're ready to begin, just click on the "start" link below, or one of the section links on the left.