I am currently applying for research ethics for a project however i cannot get my head around the correct statistical analysis for my project

The problem i am trying to answer is that there are several reference values to score a participants breathing test score against. I am hypothesizing that there will be a difference between the sets of values and after more research i could create a new set of reference values and the 5 sets of values are all calculated by different methods (some by height, some by age etc)

The two tier approach i want to look at is:

To score participants lung function test results against 5 different predicted values to see if there is a difference between them

Also i want to see to which predicted values score people score normal (between a lower and upper range of normal) to see if there is a difference

I have little amount of experience in research statistics however this was approximately 5 years ago

I have thought over this for a while but cannot get my head around it


p.s this is my first post on this forum and i apologize if its not up to scratch!