Midrange

The midrange uses only the two most extreme observations, so it is fast to compute and easy to distort. You find it with $\text{midrange} = \frac{\min + \max}{2}$. For a week of high temperatures whose smallest value is 41 degrees and largest is 77 degrees, the midrange is $(41 + 77)/2 = 59$ degrees. Because everything between the extremes is ignored, one unusually large value moves the midrange much more than it moves the mean or the median.