Weighing scores based on participation

First of all let me apologize for my lack of math skills.

I am trying to figure out how to weigh scores based on participation rate.

Data:

4 groups of people (doesnt matter how many in each group) have the opportunity to take a test.

Each group varies in participation and average score.

Example:

__Group__ ....... __Avg Score__ ....... __Participation Rate__

Group1....... 1134............... 3%

Group2....... 1101............... 9%

Group3....... 1021............... 19%

Group4....... 1001............... 70%

Group5....... 998................. 89%

There should be a way to weigh the scores based on participation giving a more acurate "higher score"

Thanks in advance for any help

Re: Weighing scores based on participation

How do you want to weight this?

Does a lower participation rate deserve more reward, or vice versa?

Re: Weighing scores based on participation

if only 3% of a large group of people participate and get a higher score than a similarly large group with a participation rate of 89%, the slightly lower score does not seem fair does it? Punishment for larger participation needs to be negated at least somewhat.

Re: Weighing scores based on participation

I may actually have it now.... What do you think?

Groupx Participation% X (Overall Average % of participations X Groupx Score) = Weight

Groupx Score + Weight = new ranking score