Hey guys I am a newbie at this, just need someone to kindly help me out..

I have a table set up.. and it looks like this..


KIND - ITEM - GRAMS - PRICE
Gold - Ring - 17.9
Gold - Ring - 25.3


So what I am trying to do is, to set a price of the ring, using a formula
So soon as I put how many gram the item costs it we give me a price

price per gram is (X)

If someone could please help me, I would appreciate it so much!

BCL Xx