Is the a question for a form created in LiveCycle Designer or Adobe Acrobat?
Have you looked at the calculation option "The field is the _____ fields: ". The blank is completed with "Sum", "Product", or 'Average" and you select the fields, including check boxes and radio buttons whose optional value is set to a numeric value.
LiveCycle has an "Avg" function. Again you need to assign numeric values to each button's value property.
The form is in LiveCycle. Being a novice I'm not sure how to assign numeric values.