You can put this solution on YOUR website!
Let n be the 5th number
n-2 is the 4th
n-4 is the 3rd
n-6 is the 2nd
n-8 is the 1st
Seems I set it up backward, but I did so so that we're solving directly for n.
(n-8)+(n-6)+(n-4)+(n-2)+n = 200
5n-20 = 200
5n = 220
n = 44