Session 4, Part B:
The Median and the Three-Number Summary

 In This Part: The Median (Low-Tech) | 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. First, place your 11 noodles in order from shortest to longest on a new piece of paper or cardboard. Your arrangement should look something like this: Next, remove two noodles at a time, one from each end, and put them to the side: Continue this process until only one noodle remains. This noodle is the median. Label it "Med": Notice that the median divides the set of 11 noodles into two groups of equal size -- the five noodles shorter than the median and the five noodles longer than the median. Another way to say this is that there are just as many noodles before the median as there are after the median.

 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