Radio buttons to set Text Field Variable in PDF Form

Currently writing a form to change the value of a text field based on the radio button selected.  The form im making has to do with "Normal Hours , Extended Hours and Holiday Hours".  So when a tech is filling out the form he selects which set of hours he is in and the form auto fills the $ amount associated with that timeframe.  So if he selects normal hours it shows a $ amount and changes if he selects a different radio button. My radio button group name is "Hours" and the field I need changed is "A01 Unit Price" I would like to do a custom calculation within the text field itself since I have 60+ field that I will need to add 3 unique variables to. Not sure the best way to accomplish this and any help or ideas would be appreciated!