Range

The range is a measure of variation, defined as the difference between the maximum and minimum values.

Consider a dataset on the weights of different breeds of dogs. The difference between the weight of the heaviest breed of dog, the English Mastiff, and that of the smallest dog breed, the Chihuahua, gives the range of the dataset.

Here, the range value of 101 kg denotes the weight variation among different breeds of dogs. The average weight of any dog breed, in this example, will fall within this dispersion or spread. 

The range relies only on the maximum and minimum, or extreme values, unlike other measures of variation. Therefore, the range has limited use because of its sensitivity to outliers and lack of robustness.

Since the range is easier to compute, it is often used to prepare control charts for manufacturing and weather forecasting applications.