This document discusses statistical techniques for analyzing data, including measures of location (mean, median, mode) which represent a single value for the data set, and measures of dispersion (range, standard deviation) which represent the spread of the data set. It provides examples of calculating the mean, median, and mode of sample data sets. The mean is most affected by extreme values, while the mode may be more useful than the median or mean for data with multiple instances of the same value. The advantage of the mean is that it uses all data values in its calculation.
3. Measures of location There are three types of ‘average’: the mean (x bar ), mode and median. These are known as measures of location. This provides a single value that represent the data.
4. Now try this Find the mean, median and mode of the following data: (a) 1, 1, 1, 3, 4, 5, 6 (b) 0, 1, 1, 1, 1 ,1 ,1, 9
5. Which of the three measures of location is most affected by an extreme value? When might the mode be of more use than either the median or the mean? What is the advantage of the mean?
6. Measures of dispersion One measure of dispersion or spread is the range . Another is the standard deviation , s or σ . The formula for standard deviation is:
