How can I prove that two samples belong to different populations (and whether they actually do)?

[Sergey Vorobyev]

Hi, David!

I'm trying to put the knowledge into practice and I think I need your help.

I'm currently evaluating a company and I'm trying to find out whether there is a connection between the valuation multiple and the number of cows (denominator). I've got a sample of similar new factories (nearly 40). I did a regression and R2 was somewhere near 0,4. However, in the graph I saw two different clusters - <1000 and >1000 cows. I did a regression on each and the results were R2 of nearly 0,02 and 0,04. Am I correct that these two samples belong to different populations (with different means and st.deviations) and that I can't analyse them as one? How can I prove it?

Thanks in advance!

 

[David Harper CFA FRM]

I'm sorry @Sergey I just don't understand the question and how cows and factories relate. Or the graph. For something like this, maybe include the whole question (or maybe i am dense), sorry.