which height glock rear sight to zero my pistol?

[nrakid88]

So my advantage arms is about an inch low at 7 yards. The glock website says each step up in rear sight height will result in 2 inch higher geoups at 25m. I THINK that translates into .5 inches higher at 7 yards? Is this correct? Im using 2/25=x/7 . Not sure if its the right formula, if so, i need the 7.3mm rear sight to be right on