Hello,

Second question for today if anyone is able to offer assistance?

I'm trying to add 3 different mean's to my data below and having trouble doing so as 2 of the data series (apologies unsure of the Tableau term for series) are already aggregate data.

Currently I have added a mean for all measurements, now I need to add a mean for the 2 data series; NoWarningMeasurements and WarningMeasurements, however as they are already aggregates I seem to be unable to then calculate an average line on these data series.

I have spent an hour + investigating and have not found an easy answer, assuming I've missed something rather simple, could someone let me know what am I doing wrong?

Thanks