Hi All - I can't figure out how to assign weights to grades in the event that one or more students don't have grades in one or more of the weight categories. For example, a student might enroll late in a school term and, therefore, may have a null grade in a "quiz" or "test" category.

Each student's total grade points are converted to percentages and stored in these columns (every 3rd col from S:AE):
S V Y AB and AE
where S = participation % earned
V = assignments % earned
Y = special projects % earned
AB = tests % earned
AE = quizzes % earned

The weights could go anywhere. They are currently in:
D3 = 15% (15% of the total grade is for participation)
D4 = 25% (25% of the total grade is for assignments)
D5 = 25% (for special projects)
D6 = 25% (tests)
D7 = 10% (quizzes)

Currently, if any cells in the points possible columns contain 0, then I'm changing the % earned cells to null, such as in this formula:
=IF(T18>0,(U18/T18)*100,"") 'if there are points possible, then convert to percent, otherwise make null

If a student has a null in any weight column, then his/her total percent column should omit that column and only use the other columns for calculating the total average or percent.

The following thread has been helpful to me, but I am unable to adapt it to this problem. Thanks!

http://www.excelforum.com/excel-gene...umproduct.html