Answer :

AL2006
Their average is  59/144 .
one way to do it is to find the average
so you add them together and divide by 2 so

first you make the bottom numbers equal so
3/8=3/8 times 9/9=27/72
4/9=4/9 times 8/8=32/72
27/72+32/72=59/72
divide this by 2 and get
59/72 times 1/2=59/144