Session 4, Part B:
The Median and the Three-Number Summary (35 minutes)

In This Part: The Median | The Three-Noodle Summary | The Three-Number Summary
Even Data Sets | Review

Another useful summary measure for a collection of data is the median. As you learned in Session 2, the median is the middle data value in an ordered list. Here's one way to find the median of our ordered noodles.

This activity requires the Flash plug-in, which you can download for free from Macromedia's Web site. If you prefer, you can continue to work with your noodles in a non-interactive version of this activity, which doesn't require the Flash plug-in.

We'll begin with the 11 noodles arranged in order from shortest to longest. We'll remove two noodles at a time, one from each end, and put them to the side. We'll continue this process until only one noodle remains. This noodle is the median, which we'll label "Med."

 Problem B1 If you could see only the median noodle, what would you know about the other noodles?

 What would knowing the median tell you about each of the first five (the shortest five) noodles? What would it tell you about each of the last five (the longest five) noodles?   Close Tip What would knowing the median tell you about each of the first five (the shortest five) noodles? What would it tell you about each of the last five (the longest five) noodles?

 Problem B2 If you could see only the median noodle, describe some information you would not know about the other noodles.

 Session 4: Index | Notes | Solutions | Video