Formula question
 

I would love it if someone could give me a formula that when I enter a
percentage into a cell it will give different percentages a certain value and
then after each cell in a range has a value (not what is actually showing on
the printout, because that would be the percentage that I entered) another
cell averages those values in a column and enters that average as a two place
decimal. (I am a Registrar at a small private school and I'm trying to get
Excel to figure the GPAs for the report cards so that I don't have to. )