I did this yesterday and got around 47% or something. I was already halfway the test when I realized I was being shown what I needed to do (that's what happens when you take such a test when you're half asleep). I'll probably try it again somewhere next week when I'm a bit more awake. *nods*
I got 85% and I probably would have had a time bonus too but I was chatting as I went and wasn't actually playing for over half the 3 minutes I took.
I take this as evidence I've spent too much time having to fill in data points and draw best fit lines while at uni.
I tabbed out a few times to write with friends on Skype, so I got no time bonus, but the accuracy was pretty good. There was one question/challenge that I completely messed up and got a very low percentage score on, though. Meh.