The Motley Fool Discussion Boards

Previous Page

Investment Analysis Clubs / Macro Economic Trends and Risks


Subject:  Re: 5 Statistics Problems To Change Your View Date:  11/25/2012  5:17 PM
Author:  LOTROQueen Number:  409564 of 591948

Hmmm. Where to begin? First, the Monty Hall scenario: They have it wrong. You have a one in three chance of being right. You pick a door. One you did not pick is opened, revealing no big prize. The game just changed. It is now a new game, 2 doors, pick one, the odds are 50/50. Change, don't does not change the odds. The only way this is not true is if Monty Hall knows which is the right door and you can game his psychology in which door he shows you. Otherwise, you are in a new game, 2 doors, equal odds.

Switching is the right thing to do. Mythbusters even demonstrated it and had a nice colored chart showing how many times the contestant would win by switching.

When presented with the Monty Hall Problem, people would be more likely to win if they changed their decision.


They built a small-scale simulator to do 50 trials each, with Adam always switching his choice and Jamie never switching. Adam won far more often than Jamie did, and Jamie explained the reason: because the player has a 2/3 probability of choosing a losing door at first, switching turns the odds in his favor.

Copyright 1996-2020 trademark and the "Fool" logo is a trademark of The Motley Fool, Inc. Contact Us