Check box selection populates a formula field

[BENHANSEN]

Hello - i am new to coding in adobe and need help with a form.  I have 3 checkboxes with calculated text fields that need to populate if checked. 

 Company Overhead - Of Cost:
$1 - 3,000 = 10%               Calculated Box
$3,001 - 10,000 = 8%        Calculated Box
$10,001 & above = 6%      Calculated Box

Can anyone help me with direction on how to accomplish this?

Thank you!

[BENHANSEN]

Here is the portion of the form.  So check box selected populates the calculated field on the right depending on which box is selected.

[try67]

What are the names of the fields involved? Are the check-boxes in the same group (ie. mutually exclusive with one another)? If so, what are their export values?