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Chapter 3: Measures of Variability
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CHAPTER 3
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Measures of Variability
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You should study the topics in this chapter if you need to review
or want to learn about
Measures of spread or variability for numerical data sets
How to compute these measures and investigate some of their
properties.
Ranges
Interquartile ranges
Mean absolute deviations
Variances or standard deviations
Coefficient of variations
The Empirical Rule
Measuring Skewness.
3 - 1 Introduction
Once you read this chapter and study these topics you will recognize that
these measures deal with only one property of the data set or distribution.
This property is the spread or variability for the data set or distribution. The
measures studied here will give some understanding of how the data varies
about some central measure. However, you will need to combine these
variability measures with other properties in order to fully understand the
true nature of the data set. Other properties for single variable data have
been studied in previous chapters and also will be investigated in later
chapters.