Running Totals omitting blank cells

[Brutium]

Hello All,

I am currently working on a marking spreadsheet for teachers where the teachers need to have running scores regardless of how many mark entries they have for their students. I am using the followin formula to get a total, but what I need is a running total so that the students get an idea of how they are doing in the class. any suggestion on how I can modify this formula so that if there are no marks inputted in cells I can still get a % of how the student is doing?

=IFERROR(SUMPRODUCT(C$7:L$7,C9:L9)/SUMIF(C9:L9,"<>",C$7:L$7),"")

Thanks for any help you can provide me....
Brutium

 

[gsistek]

I don't quite follow. Are the possible scores in C7-L7 and the student's scores in C9-L9?

 

[number kruncher]

If the max possible score is in Row 7, and the achieved scores are in Row 9, divide the current formulae by 100, and format as %

 

[Brutium]

Sorry I should have explained better.
No, the value in row 7 are weights I give to the marks, so that for example a test is worth 4 times more than a quiz. Whereas the values in row 9 are what the students get in their tests (for example 85%) coming from a second worksheet. Does it make sense?

 

[Brutium]

Again I need to be able to omit in my calculations columns (e.g. F,G,H) if there are no values in these columns and still come out with a running average based on the marks that I have for my students.
Thanks

 

[gsistek]

The formula you are using omits the blank cells because when sum product comes across a blank cell, it treats it as zero. It multiplies this imaginary zero by the cooresponding weight (equalling zero) and adds it to the total.

 

[number kruncher]

Agreed (gsistek), unless there is any information missing from this problem, the answer is already being provided by original formula.

 

[Brutium]

Thank you all....
After a closer look at the formula I concurr with all you. What fooled me is the fact that the formula only gives me the %age of the mark that I have. I guess what I really need is to have whatever mark I have to show as a %age of the Final mark and not only as a %age of the the one mark. What I am trying to explain is that if I have marks for lets say Tests, Quizzes but not Labs and the weight of the mark in Labs is 15%, then the mark that I would like to show should be based on 85% of the Final Mark. And this should be ongoing.
Did I explain myself?

Brutium

 

[number kruncher]

I think an example of your data would help your cause immensely.

 

[Brutium]

Hello number kruncher,

Would I be able to send you a private message?