Reports & Charts - Creating a Pareto Chart

I am trying to create a Pareto Chart. I've selected a "Line and Bar" for the Chart Type. I am trying to figure out how to add the line graph that showcases the cumulative percentage of events.

I assume it will need to be added into the "Report Formulas"...I keep wracking my brain trying to figure it out.

Any advise or help?

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Kelsey Poole
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