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Chapter 3: Measures of Variability
Definition: Measure of Variability
A measure of variability for a collection of data values is a number that is
meant to convey the idea of spread or variability for the data set.
The most commonly measures of variability are the range, interquartile
range, mean absolute deviation, variance or standard deviation, and the
coefficient of variation.
3-2 The Range
The first (and the simplest) measure of variability which will be discussed in
this chapter is called the range. We can only compute ranges for numerical
data sets.
Definition: Range
The range is the difference between the largest and smallest values in the
data set.
The computational formula for the range is given below and is denoted
by the letter
.
Following are some notes which one should keep in mind when dealing with
the range for a data set.