The median is the data value in the middle of the set; If there are 2 data values in the middle the median is the mean of those 2 values. Median Example. For the data set 1, 1, 2, 5, 6, 6, 9 the median is 5. For the data set 1, 1, 2, 6, 6, 9 the median is 4. Take the mean of 2 and 6 or, (2+6)/2 = 4. Median Formula