Session 5: Variation About the Mean

In Session 4, we explored the Five-Number Summary and its graphical representation, the box plot. We also explored the median, a common numerical summary for a data set.

In this session, we'll investigate another common numerical summary, the mean. We'll also learn several ways to describe the degree of variation in data, based on how much the data values vary from the mean. Note 1

Part A:
Fair Allocations

Part B:
Unfair Allocations

Part C:
Using Line Plots

Part D:
Deviations from the Mean

Part E:
Measuring Variation

Homework

Materials
You will need to have these materials in hand before you begin:

•
45 coins

•
calculator

•
several pieces of blank paper or 22" by 28" poster board

•
self-adhesive colored dots or 2" by 1.5" adhesive notepaper squares

In this session, you will do the following:
•	Understand the mean as an indicator of fair allocation
•	Explore deviations of data values from the mean
•	Understand the mean as the "balancing point" of a data set
•	Learn how to measure variation about the mean


	Throughout the session you will be prompted to view short video segments. In addition to these excerpts, you may choose to watch the full-length video of this session.


	Previously Introduced:		New in This Session:
	line plot median variation		allocation deviation from the mean equal-shares allocation mean mean absolute deviation (MAD) standard deviation variance

Next > Part A: Fair Allocations

Session 5: Index | Notes | Solutions | Video