Lets say I currently weigh 215 lbs... And want to be 175 lbs...at what weight would be 90% of my goal?

IP has changed the P1 protocol. We are now to remain on P1 until 100% of weight loss is achieved. If you are following an older protocol sheet, you can find the newest ones toward the end of stickies post

But to answer your question,
215-175=40 lbs
40 x .9 = 36 lbs
215-36 = 179