@isysedge,
#1. dotted line
You can use lineDashType to set the dash type of stripLine as a dot/dash.
#2. the red marker in every section of month like january , february … December
You can use scatter chart with color set to red.
#3. And also hover on the red marker to see the differences between the current value to the average value
You can define toolTipContent at dataSeries level to achieve this.
Please take a look at this JSFiddle for the same.
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Indranil Deo
Team CanvasJS