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URL:  https://boards.fool.com/hmmm-where-to-begin-first-the-monty-hall-30397982.aspx

Subject:  Re: 5 Statistics Problems To Change Your View Date:  11/25/2012  7:48 AM
Author:  lobodoug Number:  409502 of 567966

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 change...it 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.

The next three I do not have issues with. However, the last one.... I think I would choose treatment A, not B. And, if I were the manufacturer of treatment A, I think I would run more tests on small stones. Clearly small stones are easier to treat with EITHER medicine. The better overall results to treatment B is a factor of the significantly larger number of small stones vs. large stones in their test, not a superiority of the treatment. I am reminded of the quote about three types of lies: "lies, damn lies, and statistics". Here the statistics do not tell the whole truth as the variation in stone size seems to not be adequately considered when evaluating over-all results.

I guess editors and journalists, even at a prestigious magazine such as the Atlantic, do not understand even basic statistics.

Cheers,

Doug
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