3.11 : Midrange

The midrange is one of the measures of central tendency.  It is the value midway between the two extreme values and is typically defined as the arithmetic mean of the maximum and minimum data values. 

In this sample dataset of the sleep time of infants, the midrange can be calculated by adding the maximum and minimum hours and dividing the sum by two.

Although the midrange is relatively easy to compute, it is rarely used in statistics as it ignores all intermediate data values and lacks robustness in measurement.

The midrange is also sensitive to extreme values. In this example, a change in the maximum or minimum hours of sleep can alter the midrange. Besides, the midrange cannot be used for categorical data such as ranks or labels.

The midrange is complementary to the range or the difference between the maximum and minimum values. For instance, by knowing the midrange value and the data range, one can compute the maximum and minimum values in this dataset.