X-no-Archive:yes
Keep scratching. From
http://qsilver.queensu.ca/~phil158d/intro/montyh3.htm#prob. There is a quite
a bit of information there, including the letter from Robert Sachs, Ph.D. of
George Mason University, stating "Please help by confessing your (Marilyn
vos Savant) error and in the future being more careful".

The Monty Hall Problem

You're on a TV game show. In front of you are three doors: there's a great
prize behind one door, and nothing behind the other two. You choose a door.
Then the host (Monty Hall) opens one of the two doors you didn't choose to
show that there is nothing behind that door. It would be bad for the TV
ratings if he opened the prize door: you'd know you had lost and the game
would be over; so Monty knows where the prize is, and he always opens a door
that doesn't have a prize behind it (Monty is Canadian, so you know you can
trust him). You're now facing two unopened doors, the one you originally
picked and the other one, and the host gives you a chance to change your
mind: do you want to stick with the door you originally chose, or do you
want to switch to what's behind the other door?

Marilyn's answer)
...you should switch. The first door has a 1/3 chance of winning, but the
second door has a 2/3 chance. Here's a good way to visualize what happened:
Suppose there are a million doors, and you pick door number 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 number 777,777. You'd switch to that
door pretty fast, wouldn't you?

-----Original Message-----
From: Paveza, Gary [mailto:[log in to unmask]]
Sent: Wednesday, March 01, 2000 1:38 PM
To: [log in to unmask]
Subject: Re: OT: Probability question

Every time I hear this one I scratch my head in confusion.
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