With this type of
question draw yourself a little sketch so you can see the problem.
The LEMAC (leading edge
MAC) is at 625.6" aft of the datum and the CG is at 650" aft of the
datum therefore the CG is 650-625.6= 24.4" in from LEMAC.
As a % of the MAC this
24.4/134.5 x 100% = 18.1%