The median is the numeric value separating the higher half of a sample data set from the lower half. The median of a data set can be found by arranging all the values from lowest to highest value and picking the one in the middle. If there is an odd number of data values then the median will be the value in the middle. If there is an even number of data values the median is the mean of the two data values in the middle. For the data set 16, 15, 17, 19, 12, 11, 14, 14, 13, 11, 18, 15 the median is 14.5. It is the mean of 14 and 15 or, (14+15)/2 = 14.5.