Siefring,

If you use the NP shown on second drawing as your CG location, then you'll have the CG at 51% of MAC.
And, if you use Geistware's calculator, you'll get a Static Margin of 43.5% for a CG location at 30% of MAC.
Just type in the numbers from a typical plane and you'll see.

following is the complete formula used by Martin Simons to calculate the neutral-point of an aircraft:

NP = h0 + ns Vs ( as/aw) (1 - (de/da ))

where:
NP - neutral-point
h0 - aerodynamic center of the wing, typically 0.25
ns - stabilizer efficiency typcially 0.6 (0.9 for a T-tail)
Vs - stabiliser volume coefficient
as - lift curve slope of stabiliser
aw - lift curve slope of wing
de/da - change in stabiliser downwash angle versus change in wing angle-of-attack, typically 0.5 to 0.33

Mine is somewhat more simplified...