Weighted Grades by Category, Multiple Students/Cats - google-apps-script

Question

Looking for a way to track students grades in sheets and have their overall grades calculate depending on scores for each assignment/category.
So all assignments are 40% of the overall grade, Assessments- 40%, and Progress- 20%.
My thinking is that a script would make this much more useful and easier than a massive ifs formula.
Attached is a sample of what/how it would be set up...
sample of sheet
Thank you in advance.

Answer 1

So google sheets does have a AVERAGE.WEIGHTED formula which should make it possible for you to do what you want, hopefully. It also appears like you have set up data validation for the assignment type drop down menu and have the appropriate points displaying on the row above. (If you have not done this, then it is possible for the Pts header to be automatically updated based on your grade scale using a VLOOKUP).
Determining the weighted average should only require adding formulas to the "Overall Grade" column. Below is a formula you can use that should work for you:
=AVERAGE.WEIGHTED(D5:F5,$D$2:$F$2)
Basically, it takes the row of assignments (row 5 in my example) and compares it to a corresponding locked list where the weights appear in row 2. You will need to modify the array slightly for your purposes just so its long enough to reach as far as your row of data. This can be done by changing "F" in the formula example to be the farthest column of data. This formula can be drag-and-dropped as far down as you like on the overall grade column. It will display results like this:
EDIT:
To take into account maximum points allowed per unique assignment requires a little bit more set up but is still very doable. Basically, we can do the same thing as before but before we average the values we need to determine the values in consistent scale. For example, if a student makes an 15 on an assignment with a max points allowed of 15, they make 100%. Likewise if they make a 2.5 on an assignment with a max point allowed of 5 then they make a 50%.
We can determine this by taking the points earned / max points * 100. We need to determine these new values before applying the weights.
To make things much easier, it would be best to add a new header which provides the corresponding max points for the selected assignments. Again, this can be added to the legend and then referenced using a VLOOKUP with exact match. So something like this (if you don't like the max points row showing you can even hide the row):
Once this information is added, we will have an easier time referencing the max value per student entry. We can calculate the 100% grade scale automatically for the row with an =ARRAYFORMULA insertion. The same formula we used earlier to find the weighted average can be modified to the following:
=AVERAGE.WEIGHTED(ARRAYFORMULA(D5:F5/$D$3:$F$3*100),$D$2:$F$2)
With this new formula the new "Overall Grade" column will take into account both the grade weights as well as the max points allowed for each assignment type on a 100% point scale.