Is the graph set up to show the results from one sample or the results from multiple samples?
Multiple
In the REPORT DESIGN find your Graph, then if they don't already exist, add as many Text fields as you need for each particle size. The text for each entry will change. An example below, I use 75 for 75mm so you will need to change the 75 to each size you're interested in.
<<Let(Size = 75)>>_<<Format(<<User System Data.PC_Finer_Multiple>>,0)>>
Lastly, because of the format, your samples will run vertically (in rows) and the sizes will run horizontally (in columns).
Edit: This assumes you have PC_Fine_Multiple in your user system data.