For this example, first create a new Dashboard and add a chart. Optionally you can skip down and add the chart to an existing dashboard.
Give your dashboard a Name. Select the module you wish to connect to and then click the Create Button.
Select how you want to display your data. In this case a Bar Chart.
Click on the "Click Here" to bind to the data you want to use for your chart.
Click on Configure Values to show the list of fields you can choose to bind to. Then select the field you wish to use – In this case Root Cause.
For Arguments also choose RootCause
For Hidden Dimensions choose Cancelled
Choose these setting with the Interactiviy gear
Use these settings for the Option Gear Common section. You wil need to give the graph a name in the Caption box
This is where you will decide if you want to Rotate the graph
Here are the settings available in the Axis X section
Here are the settings available in the Axis Y section
Seems if the point here is to show how to create a graph, the end result should be shown.
For further assistance with Dashboards use the links at Dashboards