this is my first time posting, so I hope I don't breach protocol, apologies in advance if I do.
I have recently come across a problem in moodle when calculating grades using weighted mean of grades. We are currently using moodle 2.9. In our previous version (2.6) we used the same method for grades and the calculations came out OK. I think we have the problem "solved" but we don't know where to go to enable the solution inside the code or database (likely some sort of setting that was missed). So, on with the problem:
When calculating the weighted average, moodle will weight the grades in a category properly. When it goes to the course grade, it looks back at the categories and sees that they have a grade in them. It then assumes that 100% of the grades are in as it only looks at the parent categories, not the subcategories. Doing the math by hand has confirmed that this is the case as I was able to replicate the numbers moodle gets for the grades.
In our old version of moddle (2.6), we had an option to "Aggregate including subcategories", however, in moodle 2.9 we no longer have that option. I am enclosing 2 screen shots, 1 from each, from where I assume the problem lies. These are from the Site Administration -> Grades -> Grade category settings area. If somebody could help explain where I need to enable the setting so they are selectable, I would be very thankful. We are trying to avoid a teacher "tech-heavy" solution as we have several teachers who are petrified by technology. This means no making a "graded" and a "non-graded" folder and working the math out with each grade that is entered.
We tried changing the skins back to the default in case it got hidden but no joy.