Hi, I guess you have placed PCT dimension in the column of Bar chart, so when you select multiple PCTs you are getting multiple bar. If you remove PCT from column BAR chart, All the selections automatically aggregate based on your measure aggregation settings.
It will be easy to understand if you can post a screen shot or packaged workbook.
It worked! I removed the PCT dimension and then changed the 'measure values' from SUM to AVG.
Thanks so much! I can't believe it was so simple.