♣8♣Elements of Descriptive Statistics
8.1. Measures of Central Tendency
Ameasure of central tendency is a single value that attempts to describe a set of data by identifying the central position within that set of data. As such, measures of central tendency are sometimes called measures of central location. They are also classed as summary statistics. The mean (often called the average) is most likely the measure of central tendency that you are most familiar with, but there are others, such as the median and the mode.
The mean, median, and mode are all valid measures of central tendency, but under different conditions, some measures of central tendency become more appropriate to use than others. In the following sections, we will look at the mean, mode, and median, and learn how to calculate them and under what conditions they are most appropriate to be used.
8.1.1 Mean
Probably the most used measure of central tendency is the “mean.” In this section we will start from the arithmetic mean, but illustrate some other concepts that might be more suited in some situations too.
8.1.1.1 The Arithmetic Mean
The most popular type of mean is the “arithmetic mean.” It is the average of a set of numerical values; and it is calculated by adding those values first together and then dividing by the number of values in the aforementioned set.
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