# Day 3: Dispersion

October 16, 2008 by kltangen

Filed under 10-Day Tour

We found the middle of the group because most people score about the same on any variable we measure. Now that you’ve found a representative for the group, how representative is the mean? Is the group unified and nearly everyone has the same score? Or are there wide fluctuations within the group? We want one number that will tell us if the scores are very similar to each other or if the group is composed of heterogeneous scores.

- There are five measures of dispersion:
- Range
- Mean Absolute Deviation (Mean Variance)
- Sum of Squares
- Variance
- Standard Deviation

NOW YOU CHOOSE:

Day 3: Dispersion

A Bit More About Dispersion

Even More About Dispersion

Range

MAD

Sum of Squares

Variance

Standard Deviation

How To Calculate

Range

MAD

Sum of Squares

Variance

Standard Deviation

Formulas For Dispersion

Practice Problems

More Practice Problems

Basic Facts About Dispersion

Audio: Lectures

Vocabulary

Quiz 3

Summary

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