I think you'll find some excellent answers he
http://www.mvps.org/dmcritchie/excel/validation.htm
A big part of what will likely help you with your homework is a Google
search. In this case I used this exact search, including the quote marks:
"data validation" using a formula
and I quickly found Dave's reference.
************
Anne Troy
www.OfficeArticles.com

"account via OfficeKB.com" <u15495@uwe wrote in message
news:56eba90ca12c7@uwe...
I am having a problem with a formula: It says to do under data, validation,
and in settings under allow choose custom then in the formula box, this is
where the problems i need a formula then determines that the value in cell
b10 is less than or equal to 150% of the value in b9. Please help i have
tried everything.