Measures of Variability
Two measures of variability are used most often in business. Here, variability refers to how much the values vary around the measure of central tendency. One measure of variability—the range—is quite simple. The other—the standard deviation from the mean—is rather complex, but it’s presented simply here.
The range is represented by two values: the lowest in the array and the highest in the array. If possible, always consider the range along with one or two measures of central tendency. For example, let’s look at the hourly salary ranges of our two groups of consultants, along with the mean and median for each group.
In Case A, the range is more tightly distributed around the mean and the median. At $41 ...