I'm not sure I capture your question exactly, but tried to understand.
I created calculated field as below. to understand minimum number of service to get profit.
int(avg([Over Head])/((sum([Charge])-sum([Indirect])-sum([Direct]))/COUNT([Number of Records])))+1
Then add X-axis ref line.
(** attached workbook made by version 9.0)
If you can attach sample sheet as packaged workbook and provide the Tableau version you are using, that helps more.
Cost_Analysis.twbx 59.0 KB
The min number needed for profit would be greater than the 201401 data point. I know how to create the red line to show what my needed profit would be, but i want my line to extend to the needed profit line to make my visualization look cleaner.