The measures of central tendency do not always show the real picture. Take for example, the following numbers

35, 35, 35, 35, 35

and

20, 25, 30,45, 55

The mean of both the series is 35. That is 35 is representative of both the series. However, there is variability in data. In the first series, all the values are equal to 35, in the second one, they vary and none of the values is 35. So, we say that dispersion or variability exists. We can find this dispersion amongst the values and between the values and the mean. The methods to find them are the measures of dispersion. They are

1. Range

2. Quartile Deviation

3. Mean Deviation

4. Standard Deviation

5. Lorenz Curve