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Joined 10 months ago
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Cake day: September 2nd, 2023

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  • Safety rules are written in blood. When you spend at least 8hours/day doing the same thing, even if that thing has a very small chance of generating an accident, that’s a lot of time spent doing something risky. Everyone has bad days, any one of those could kill you/severely injure you if you don’t take safety protocols seriously.
















  • I tried to answer but idk why Lemmy failed to post it, so I’ll make a tldr instead.

    TLDR:

    Instead of reasoning I used actual statistics equations and you are correct: the chance in the coins case is 1/3.

    However, I was misguided assuming that both the “girl and boy” problem and “coins” problem are the same, when in fact they are not.

    In the “coins” case, the statement “at least one of them is heads” has a probability of 3/4. In the “girl and boy” case, the statement “the child that opened the door was a boy” has a probability of 1/2.


  • You didn’t eliminate BG and GB where a girl opens the door though. If you do that, then the answer is 50%. Because you remove half the probability from BG and GB and you remove none from BB.

    I know you didn’t eliminate those cases because you said “That leaves us with 3 possibilities with equal probabilities”. That would be false, BB is twice as likely.


  • You can’t just end the experiment if the randomly chosen child doesn’t “fit the parameters”, by doing that you aren’t accounting for half the girls in the whole event pool. Half of the girls have siblings that are girls.

    Being 2 girls was a possible event at the start, you can’t just remove it. This time it happened to be a boy who opened the door, but it could’ve been as likely for a girl to open it.

    If it was phrased like “there are 2 siblings, only boys can open doors. Of all the houses that opened their doors, how many have a girl in them?”, then it will be 2/3. In this example, there is an initial pool of events, then I narrowed down to a smaller one (with less probability). If you “just” eliminate the GG scenario, then the set of events got smaller without reducing the set’s probability.