the median is equal to the average of the numbers
add up all of the numbers and divide that by the total number of numbers to get the average, or median
for example: the average of 13,20, 15, and 23 would be (13+20+15+23)/4=17.75
if you have the sequence of 4, 8, 10, 5, and 9, the average would be (4+18+10+4+9)/5 = 9
Hope that helps!