Economics Problem Help

Hello Everyone,

Im stuck on the problem below, can someone please direct me:


http://img59.imageshack.us/img59/9961/unleddg.jpg

define P, AOC, N and S please

I now see what you were asking, my appologies.

Ok here is what I come up with, can someone confirm this is correct please?
http://img695.imageshack.us/img695/6990/unledxs.jpg

thanks for your help!!