Wow totally messed up Dalton's Law and made a hybrid with Rault's law.
Pressure Total = P1 + P2 + P3 + Pn
Partial Pressure 1 = Chi (Ptotal), where Chi is the mole fraction of Compound 1 ( mole Compound 1 / Mole total)
Rault's Law => VP = Chi1 ( Po1) + Chi2 (Po2) + Chi3(Po3) + Chin (VPon)
As for any confusion about mole fraction /pressure fraction, note that the two are proportional.