Averaging group of numbers worth different values

[DentonHTHS]

Hi, I am working on a marking sheet and I have one section of assignments that are worth different amounts. Most of the assignments are out of 20 but a few are out of 50 because I wanted them to be worth more. I am trying to get a final mark in this category so I want to average out the marks but can I do that while still weighting these assignments at a higher amount? If I converted them all out of 100 they would all be equal in value.

Hopefully this makes sense and I am not missing something really obvious. I think I may have been looking at these numbers too long!

 

[PaddyD]

If you've set it up so they're worth more, why do you need to weight them back down? Isn't that self defeating?

Tell us, in words with a worked example, the kind of effect your after.

 

[DentonHTHS]

Okay, the values are
A B C D
20, 40, 10, 34.

Let's say that B and C are out of 50 while A and C are out of 25. I want to keep the extra value of B and D but in the end I want to get a final mark for all the data in the set out of a mark of 20 (20% being the value of this particular section). I could add them up but how do I include the total value of the assignment? On paper I would add them all up and divide by the maximum value of the assignment times 100. Not sure how to set this up so that Excel knows the total value regardless of how many different assignments I put in there. (If I had 8 different assignments in this section instead of the 4 up above.)

 

[PaddyD]

well if your results are 20% of the total, just add them up & * 0.2

…or am I still missing something?