Please stop using "I don't know where the QR will take me" as an excuse. Any decent scanning app shows the QRs content before asking the user to act upon it. Who would want an app that instantly saves a vcard to their contact list, or opens a url as soon as they scan it?
The mouse has always felt 'different' to me on OSX. I think this explains half of it, the other part being that the hotspot pixel for the cursor isn't actually at the tip, but two pixels down.
For the sake of completeness, my first steps before sorting and plotting were to:
1. take the mean, median and mode of each set,
2. try and fail to use more sophisticated statistical analysis [1],
3. have a look at the minimum and maximum value for each set.
By #3 I already had a good enough guess, but I felt I had to see it.
[1] In fact, could anyone point me to a refresher? I'm talking about distribution curves, regression, that kind of thing. I seem to have lost hang of it — couldn't pass my own "5 minutes to implement the simple thing" criterion.