Measures of central tendency used to describe the average income of people across the United States have both strengths and weaknesses. On the plus side, they provide a good general idea of incomes in a particular geographical area. This can be useful for making generalizations for decision-making purposes. For example, knowing that the mean income in the area is $25,000 immediately identifies that it is a relatively low-income area. However, on the minus side, all of these numbers are generalizations of one kind or another; not one of them is precise. The mean is an average, and it is possible to look at an average and have no idea what the highest and lowest figures were. The median is the middle figure, which again provides no idea of the extremes at top and bottom. The mode is the most frequently occurring figure, which gives an idea of trending but like the other two measures is not precise. Moreover, in an area where incomes are not distributed evenly, these three measures can differ markedly from one another, thus possibly being more confusing than helpful. In the last analysis, none of these generalizations is as accurate or non-misleading as the actual figures-the entire list of all the incomes in the region. However, that list is too large for the average reader to do anything with. If he did have the means the analyze it, the first thing he would do is apply the measures of central tendency so that he could generalize sufficiently to get a broad idea of the overall salary levels in the area. Thus, measures of central tendency are most valuable for their ability to reduce a vast number of figures to a comprehensible generalization, and they are least valuable for the fact that a generalization is never completely accurate or comprehensive but only identifies a trend.
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