A subject is corrected for near vision at 25cm from the front plane surface of the lens by a plano-convex trial lens +8.00D. The final lens is dispensed in curved form with a +11.25D front curve. What back vertex power must be ordered to so the finall lens duplicates the effect of the trial lens? Assume that both the trial & final lens are a made in glass of n=1.5 and an axial thickness of 6.0mm