Hello Zach,

You can use UnknownValuePltting property of the Line series and set it to LinearInterpolate like this:

  .Series(s =>

        {

            s.Line("ActiveCustomers").UnknownValuePlotting(UnknownValuePlotting.LinearInterpolate)

                .XAxis("Label")

                .YAxis("Count")

                .ValueMemberPath(cc => cc.CustomerCount);

        })

this property is described here:

http://help.infragistics.com/jQuery/2012.2/ui.igdatachart

just go to the tab “Options” then expand “series”.

Please let me know if this helps.