# Chapter 1. Mean and Median

## Introduction

Statistical Applets

Click below the line to add an observation. The red arrow marks the median. The green arrow marks the mean. When the median and mean are equal a single yellow arrow is shown. You can move a point by dragging it along the line, or remove it by dragging it to the trash. At the left you can enter new values for the upper and lower limits of your distribution and click the UPDATE button to save them.

Click the "Quiz Me" button to complete the activity.

A description of a distribution almost always includes a measure of its center. The two common measures of center are the mean and the median. This applet lets you explore the relationship between the mean and median as the points in a dataset change.

### Question 1.1

Experiment with the applet to answer the following question: with two values, the mean and median are 70CLCpBLrVbDCFBRNlN3CbUQVcOA8IvWMU9RkQ== exactly the same.

2
Try again.
Incorrect. See above for the correct answer.
Great job.

### Question 1.2

S/IXPyX+tHxajLnnOPpl6fZysuzAnNypjjqWjGj0JOBJvP6FVCSwrcE4evZr2goaSr2eCoZbNv5UgVEf3BvwgcSaWbQzh+lxahkssydoFL57fF/TegS2ycRs47/u3n/aawq0wpwRjv/SG4XafK7Ee9p4t+cTDUZjJMqu0AIEIJfdEbinVhnQVsvfkgocjRBJodWDZhQv5mHn0dRcdU/BLrXnyQD8smE6dEqT3WTB9VoDZmx0LLAn/6gX6fj1f93iEmorfDxL+rf5ZZUOiLdChp1jnmAGbyipz/EdHfgP74bePn1YeMiqyiQbr3N6N7R/ZzPFNzPXmjR9dVsg4AwrDtl2xYg3YHX0dLB3o7KhWZUMvQbIeORNyvgbyzCbpTh52P+lkWn7Ba/eUENni1FU4V+HZUm2S4jZSw1T+LIeYFn8PbLfsPxUgNwD10CLRHxARr5u+GNm9n8dQJgpcIjcJ7IetxSmmVcS0x+93ePIWXw=
3
Great job.
Add 5 points where the median and median are identical.

### Question 1.3

Now add another point on the far right side of the line. This has the effect of making the mean VfuRCwlTAeoKF9pu9xJtP/pVxaesXIFfyDyNuf+wz7qgt9RNZwn83w== the median.

2
Try again.
Incorrect. See above for the correct answer.
Great job.