Hello @arnaudsteyaert ,
To use the confidence interval for the geometric mean for graphing, you need to first create a column in your data table with the formula. You can see the details of the calculation on the following page.
https://blogs.sas.com/content/iml/2019/10/02/geometric-mean-deviation-cv-sas.html
Once you have created the column, you can create a graph by following these steps.
--Select Graph --> Graph Builder
--Select Y and drag it to the left of the Y axis.
--Select Time and drag it to the bottom of the X axis.
--Select Group and drag it to the Overlay Zone
--Select Columns with Lower and Upper Confidence Interval Formula and drag them to the Interval zone.
--Select "Geometric Mean" in the "Summary Statistics" section.
Please see the attached sample data for your information. I hope it helps.