Median

The median of a numeric data set is the value that separates the higher half of the values from the lower half. For a finite list arranged in order, it is the middle value when the count is odd and the average of the two middle values when the count is even. Unlike the mean, the median is not skewed by extreme outliers, which makes it a common measure of central tendency for income, house prices and other data with a long tail. It also extends to random variables and probability distributions as the value below which half the probability mass lies.