I am trying to write a frequency calculation so that I can display the results on a pie chart. I have four options to make up 100% of sales transactions: sold, rejected, canceled, and re-scheduled.

I would use LODs to get the % of total - see https://jimdehner.com/2023/09/09/bgs-session-8-special-calculations-lods/

when you have your tableau workbook ready, if there are still question be sure to attach the twbx so we have your base to work from