Thank you for your post. I have been looking into it and I can suggest using the trend line of the BarSeries. You can read more detailed information regarding the trend lines in the XamDataChart, here in our documentation: http://help.infragistics.com/NetAdvantage/WPF/current/CLR4.0/?page=xamDataChart_Trend_lines.html. Also I have created a sample application for you, that shows how you can implement this functionality.

Please let me know if you need any further assistance on the matter.

Sincerely,

Krasimir

Developer Support Engineer

Infragistics

www.infragistics.com/support

Example: Items per month with a line graph overlay of an average against another property per data item.