How are Avg Rs for XBarR-Charts with subgroups of varying size calculated ?
HelloWhen I create an Xbar Chart with sub groups of various sizes defined by a label, I am getting different Avg Rs for the different subgroups (see graph). How exactly are the avg Rs (displayed in the R Chart as the Center line) for a given subgroup calculated ? Originally I thought they were the mean of the ranges within a subgroup, but there are several occasions (in the graph below), where the...