New Summary Report Calculation

In the April release it mentions a new way to calculate aggregate data in a summary report that would solve the "average of averages" problem. But there is no reference or name of a function on how to do actually do this. In my table I have a profit margin field, but in my summary table which is by month, I don't want to just take the average of that field, as it will give me an incorrect number. I want to do the formula on the actual summed data. Is this possible now? Or am I misunderstanding the release?

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Nathan Allan
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