meta user
network profile
| bio | website | |
|---|---|---|
| location | Bellevue, WA | |
| age | 76 | |
| visits | member for | 2 years, 8 months |
| seen | May 7 at 9:19 | |
| stats | profile views | 87 |
|
Dec 25 |
comment |
2 slightly different situations in which 2 coins are tossed. Does the knowledge of an observer effect the probabilities of the outcomes? whereas I was presenting situations where to begin with there already is one girl. So I visit a family who have two kids. One comes in the living room to meet me. She's a girl. So I'm wondering to myself if the other child is a girl -- and thinking that the probability of the other child being a girl is 1/2. There is no boy-boy. Only girl or boy. Some have set the situation up as examining a random sample of 2-child families. But there is no study. This is a one-off. I just happened to visit this family one day. Examining the gender or number of their kids was not on my mind. |
|
Dec 25 |
comment |
2 slightly different situations in which 2 coins are tossed. Does the knowledge of an observer effect the probabilities of the outcomes? @Rahul Sure I want what you have to say. In my last comment both of us were dealing only with situation A. You aren't disagreeing with my argument there, are you? As for the observer's strategy, I don't believe I've left room for him to have one. So please clarify. As for probability spaces, I was familiar with them before I asked the question -- I just don't agree that they are of much use here, or have been used in a way that doesn't reflect the situations I've posed. For example, in the one-or-two girls problem, some were allowing for boy-boy to be an original possibility -- |
|
Dec 25 |
comment |
Series that converge to $\pi$ quickly J.M.: Which is the faster, Ramanujan's or the Chudnovsky brothers'? |
|
Dec 25 |
awarded | Promoter |
|
Dec 25 |
comment |
2 slightly different situations in which 2 coins are tossed. Does the knowledge of an observer effect the probabilities of the outcomes? @Rahul: In A the observer only knows about the one coin he looks at. He tells me that at least one of the coins is heads, which in A must mean that the coin he looked at is heads. IOW "At least one of the coins is heads" DOES imply "The first coin is heads". No? |
|
Dec 24 |
comment |
In a family with two children, what are the chances, if one of the children is a girl, that both children are girls? @Jonas I don't agree that I left any ambiguity between "one particular child", "at least one child", and "exactly one child". Look at the context: "I had heard that he had 2 kids and one was a girl. I was going to visit him soon and was wondering about the other child. Girl? or boy?" Clearly this implies that I believed he had at least one girl, and had no knowledge about the other child. |
|
Dec 24 |
comment |
2 slightly different situations in which 2 coins are tossed. Does the knowledge of an observer effect the probabilities of the outcomes? @Rahul Thank you for not giving up on me. I thought I'd written the question (before the edits) to indicate that in A and B the coins had already been tossed, with at least one heads in both cases, as reported by the observer. In A, the situation is such that the one coin the observer looks at IS heads; in B at least one of the 2 coins he looks at IS heads. Those are givens. Their probabilities are irrelevant, IMO. Therefore my claim that I receive exactly the same information from the observer in both cases. |
|
Dec 24 |
revised |
2 slightly different situations in which 2 coins are tossed. Does the knowledge of an observer effect the probabilities of the outcomes? added 331 characters in body; added 5 characters in body |
|
Dec 24 |
comment |
2 slightly different situations in which 2 coins are tossed. Does the knowledge of an observer effect the probabilities of the outcomes? @TonyK So what are the probabilities for A and B as of my first edit? I'll now edit again and have the observer look at both coins in B and pick one, about which he will tell me, if it's heads, "There is at least one heads", or if tails, "There is at least one tails". What is the probability of the other outcome being heads or tails, respectively? |
|
Dec 24 |
comment |
In a family with two children, what are the chances, if one of the children is a girl, that both children are girls? @Jonas "How did you hear that one child is a girl?" I wrote "I had heard that he had 2 kids and one was a girl." I think that implies that someone told me that (or possibly wrote that to me in a letter or email), and that's all I know about my nephew's children. Isn't that the standard interpretation? |
|
Dec 24 |
comment |
2 slightly different situations in which 2 coins are tossed. Does the knowledge of an observer effect the probabilities of the outcomes? With my edit I believe I've removed any possible analogy with the Monty Hall problem. How about it? |
|
Dec 24 |
awarded | Editor |
|
Dec 24 |
revised |
2 slightly different situations in which 2 coins are tossed. Does the knowledge of an observer effect the probabilities of the outcomes? added 602 characters in body; added 5 characters in body |
|
Dec 24 |
comment |
2 slightly different situations in which 2 coins are tossed. Does the knowledge of an observer effect the probabilities of the outcomes? @Willie It seems absurd to me that the probabilities could be different due to the different knowledge the observer has of the outcomes: knowing about only one of the coins versus knowing about both the coins. What he tells me is identical (and truthful) in both situations: "At least one of the coins is a head". |
|
Dec 24 |
accepted | Is Knopp's “Theory and Application of Infinite Series” out of date? |
|
Dec 24 |
accepted | Amicable pairs: any use for them yet? |
|
Dec 24 |
accepted | What is limit of $\sum \limits_{n=0}^{\infty}\frac{1}{(2n)!} $? |
|
Dec 24 |
asked | 2 slightly different situations in which 2 coins are tossed. Does the knowledge of an observer effect the probabilities of the outcomes? |
|
Dec 23 |
comment |
In a family with two children, what are the chances, if one of the children is a girl, that both children are girls? I believe that last word should be "girls"? |
|
Dec 21 |
awarded | Nice Question |
