And now if I can multiply this by the largest bar, I will have what I need. I tried different combinations with Max and Aggr, but I was not successful. In the attached file I just hard-coded the value (3705) I want, but this will not work if I filter.
Let me know how I can replace the 3705 with a formula, or if there is a better way to get this cumulative percent line on the graph.
It might make it a little more complex in that I am using a calculated dimension for the bars instead of a field (=aggr(COUNT(DISTINCTProduct),Customer) ).