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comment by wasoxygen
wasoxygen  ·  3596 days ago  ·  link  ·    ·  parent  ·  post: For everyone in the book exchange: The Necessity of Marginalia

Yes, and our number agrees with the footnote in the book, but I still don't follow the explanation there. Where did the number 1.706 come from?

Simpson's Paradox is my favorite statistical anomaly.





b_b  ·  3595 days ago  ·  link  ·  

    Where did the number 1.706 come from?

I'm not sure either. I had tried to manipulate the equation to read something of the form P(A)/(1 + P(A)), but I couldn't find an obvious way to do that. Also, it doesn't work the other direction. That is, the probability of the car being green when it's reported green does not equal the probability of the car being reported blue divided by 1 plus that probability, so it's certainly not a general solution to the problem, but perhaps a weird coincidence of the way he did the arithmetic.