midrange
n. the average of the lowest and highest scores in a set of data. The midrange is a measure of central tendency more prone to bias than the mean, median, and mode because it relies solely upon the two most extreme scores, which potentially are outliers. For example, consider the following hours per week spent using a computer for five individuals: 6, 10, 15, 21, and 35. The midrange is 20.5, the mean is 17.4, and the median is 15. The midrange score thus is larger than the mean or median due to the influence of the outlier of 35 hours.