Median and Mean

Prerequisites
What is Central Tendency, Measures of Central Tendency

Learning Objectives

  1. State when the mean and median are the same
  2. State whether it is the mean or median that minimizes the mean absolute deviation
  3. State whether it is the mean or median that is the balance point on a balance scale

In the section "What is central tendency, we saw that the center of a distribution could be defined three ways: (1) the point on which a distribution would balance, (2) the value whose average absolute deviation from all the other values is minimized, and (3) the value whose squared difference from all the other values is minimized. From the simulation in this chapter, you discovered (we hope) that the mean is the point on which a distribution would balance, the median is the value that minimizes the sum of absolute deviations, and the mean is the value that minimizes the sum of the squared values.

When a distribution is symmetric, then the mean, and the median are the same.