I think you should rephrase the question into something like:
If your screen broke for UNEXPLAINABLE reasons, what colour was your M92?
One is not really interested in cases when the device was dropped, for example.
Then, I think there should also be another two fields in the pool:
"I own a black one (NOT broken)"
"I own a white one (NOT broken)"
So that in the end we know the ratios:
"broken black / all black"
"broken white / all white"
Well, on second thought, one could also imagine adding yet another two fields in the pool:
"A black one broken due to heavy mechanical accident (e.g. dropped)"
"A white one broken due to heavy mechanical accident (e.g. dropped)"
Last edited by pepe_alter_ego; 07-05-2013 at 08:59 AM.