Can someone please explain the roll return calc in 11-A in reading 36 EOC Qs? I understand the RR(9,1), but how do you get the 9,2; 9,3; 9,4. Also, I don’t get how you assume to go through those three add’l calcs to get the average they are looking for?

Sorry, subject should be CFA Reading 36

They take the Jan - Sept numbers, add up and divide by 9. Then they take Feb - Oct number, add up and divide by 9. Same with Mar-Nov & April - Dec. Once you have these four numbers they add them together and divide by 4.

Are we assumed to always take this approach to a roll return question? I think I am missing something in the reading.