Plan: filling the grid with pretend random heads and tails.

That exercise worked well, I thought. Reading as written, the number of runs of four came out to about 4.5%; the expected value is 1/8 = 12.5%. Reading vertically, the observed fraction was about 11%. I think the psychological point was made – it’s hard to write that fourth H after three, but it does happen, at a predictable rate even if not at predictable times. We calculated that 10 heads in a row happened once in a thousand tries, so there would be about 15 people who thought themselves lucky if every student on campus did the experiment.

We had a hard time after that, first on why double-or-nothing doesn’t work, then on the probability and science behind hundred-year-storms, the increasing frequency of natural disasters, like, you know, earthquakes you know …

Last class before Thanksgiving and we were all too tired to think.

 

---

blog home page