While we can change the number of decimal places and font size for the data on Y-axis, I am unable to find a way to do the same for data/parameter which is used to 'group' the data (Group Y) in Graph Builder. More specifically the Group-Y is the RHS Y-axis in Graph Builder. (JMP 13.2.1)
Good question! My work around is to create a column containing a binning formula with the numbers formatted however I want. That does not help with font size though.
It works even without creating a new column. We just have to change the number of decimal places by right click on column heading then use Column Info (select 'Fixed Dec' under format and set Dec to 0 etc).
It would help if JMP provides the option to do it on the axis itself with font change etc too.