I understand with multiple levels the sum needs to be divided by 2 (2nd level), 3 (3rd level), etc.
This works for sums but is it the same for averages? For example"
Details for group 1 are 2,5,0,9 - group 1 average is 4
Details for group 2 are 15,0,0,5,0 - group 2 average is also 4
The average for group 1 and group 2 is 4 but according to the sum method we would divide this by 2 ?
