The median of a list of number is the number in the middle of the the list. Pretty self explanatory.
The median of 26, 26, 28, 29, 31, 33, 35, 36, 37, 38, 40, 42, 43, 46, 48 is 36.
There are 15 number in this list and 36 is the 8th, seven on the left of 36 and seven on the right.