Objective
To find mean, median, mode, and range
Essential Understanding You can use different measures to interpret and compare sets of data.
One way to summarize a set of data is to use a measure of central tendency. Mean, median, and mode are all measures of central tendency.
The measure of central tendency that best describes a data set may depend on whether the data set has an outlier. An outlier is a data value that is much greater or less than the other values in the set. Below is a review of mean, median, and mode, and when to use each as the measure of central tendency.
Measure | When to Use |
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The mean equals
|
Use mean to describe the middle of a set of data that does not have an outlier. |
The median is the middle value in a data set when the values are arranged in order. For a set containing an even number of data values, the median is the mean of the two middle data values. | Use median to describe the middle of a set of data that does have an outlier. |
The mode is the data item that occurs the most times. A data set can have no mode, one mode, or more than one mode. | Use mode when the data are nonnumeric or when choosing the most popular item. |