I was perversely flipping through the Parade section of my Sunday newspaper when I stumbled upon Marilyn vos Savant’s “Ask Marilyn” column. Even more perversely, I read it. It wasn’t a total loss, though, because it appears she made another mistake, even worse than the one you pointed out in a very entertaining column a few months ago. Here’s the question:
Best of Chicago voting is live now. Vote for your favorites »
ANSWER: Yes; you should switch. The first door has a one-third chance of winning, but second door has a two-thirds chance. Here’s a good way to visualize what happened. Suppose there are a million doors, and you pick door No. 1. Then the host, who knows what’s behind the doors and will always avoid the one with the prize, opens them all except door #777,777. You’d switch to that door pretty fast, wouldn’t you?
PS: If the questions she answers are any indication of the intellect of the general population, this country is in a lot of trouble.
Art accompanying story in printed newspaper (not available in this archive): illustration/Slug Signorino.
