How to populate a custom field based on certain criteria

How to populate a custom field based on certain criteria

Hi,

I am looking for the formula it would take to perform this action:

I would like to create a formula field, within the Accounts module, that returns Boolean True or False, based on the Status within the Deals module. If the Deal status is "Closed-Won", then the custom field populates True, if the Deal status is any other, then false. 

How would I make this happen? thanks!