Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The Time Everyone “Corrected” the World’s Smartest Woman (2015)

priceonomics.com

Post reply on HN
Print view View original

151–160 of 331 posts

Re: The Time Everyone “Corrected” the World’s Smartest Woman (2015)

#151

Post by mkl »

FabHK wrote: post #125
hn_throwaway_99 wrote: post #116

Earlier quoted context omitted.

In this case, though, I don't believe it's just calculation vs. intuition. The reason the 100 or million door problem helped me understand was because it clarified an implicit rule of the game: that the door the host chooses to open is not random . If it were random, it would make for a very boring game ("Uhh, there's the prize, you win, I guess that's game over.") Once I understood that the host would only ever open…

Indeed, that is a crucial bit of information that is not made explicit in the original framing of the problem.

I think it's made pretty explicit. In this version: "Then, the host, who is well-aware of what’s going on behind the scenes, opens door #3, revealing one of the goats." The host has to open a door that doesn't show the car.

Re: The Time Everyone “Corrected” the World’s Smartest Woman (2015)

#152

Post by listenallyall »

hellbannedguy wrote: post #143

I still don't get it. 1. Three doors. 2. Two doors have a goat, and one has a car. 3. The contestant has a 1/3 chance of winning the car? 4. The contestant loses. 5. New game, and odds? 6. There's a 50/50 chance of winning? (I'm assuming Monte Hall has no clue to where the car is. He is just opening doors.) 7. Could someone explain it to me, and thanks in advance. (Off topic but a fawn had two babes in my back yard.…

Monte Hall DOES have a clue where the car is, and is NOT "just opening doors"

With the full knowledge of where the car is, Mr Hall opens a door that is NOT the door the contestant chose, and is also NOT the door containing the car.

Re: The Time Everyone “Corrected” the World’s Smartest Woman (2015)

#154

Post by antonvs »

froh wrote: post #95

> Whereas only 8% of readers had previously believed her logic to be true, this number had risen to 56% by the end of 1992, writes vos Savant; among academics, 35% initial support rose to 71%. that 71% leaves 29% of _academics_ not getting the elementary math of the problem. I'm baffled this is _that_ hard?

I think the lesson is that the are a lot of bad academics out there, who either repeat what they've been told without understanding it themselves, or whose confidence exceeds their ability, Dunning-Kruger style.

Re: The Time Everyone “Corrected” the World’s Smartest Woman (2015)

#156

Post by edoceo »

lamontcg wrote: post #139
lachstar-x wrote: post #102

Earlier quoted context omitted.

Can you help me understand - in my view the choice to switch doors or keep the same door is irrelevant, because even if you keep the same door you're making a choice that is now 2/3 of the right answer. If you switch or keep, you're still choosing from two doors that contain a car and a goat. The other door is no longer relevant and doesn't affect the new state at all. It's your perspective (narrowing the choice down…

Look at it from actual door, first guess door pairs -- which are the random uncorrelated events: 1,1 - switch loses (host may have shown door #2 or #3) 1,2 - switch wins (host showed door #3) 1,3 - switch wins (host showed door #2) 2,1 - switch wins (host showed door #3) 2,2 - switch loses (host may have shown door #1 or #3) 2,3 - switch wins (host showed door #1) 3,1 - switch wins (host showed door #2) 3,2 - switch…

incredibly succinct, thanks.

Re: The Time Everyone “Corrected” the World’s Smartest Woman (2015)

#157

Post by someguydave »

mkl wrote: post #151
FabHK wrote: post #125

Earlier quoted context omitted.

Indeed, that is a crucial bit of information that is not made explicit in the original framing of the problem.

I think it's made pretty explicit. In this version: "Then, the host, who is well-aware of what’s going on behind the scenes, opens door #3, revealing one of the goats." The host has to open a door that doesn't show the car.

Yeah - I don't think that statement clarifies. The rule that the host will never reveal the prize should be made explicit.

Re: The Time Everyone “Corrected” the World’s Smartest Woman (2015)

#158

Post by leephillips »

failwhaleshark wrote: post #99

This reminds me of the time my entire family screamed and shouted that I was wrong that buying two different lottery tickets slightly more than doubles the total (infinitesimal) odds of winning over just one. 1 in a zillion vs slightly greater than 2 in a zillion because eliminating one choice reduces the pool by one for the next choice.

If you are talking about a simple lottery with N tickets and a fixed probability of any one ticket being the winner = 1/N, then the screamers were correct. To see this, imagine that there are a total of two tickets (N = 2). You buy one ticket. The probability that it is the winner = 1/2. After buying the second ticket, is your probability of winning somehow > 1? Or has it exactly doubled?

Re: The Time Everyone “Corrected” the World’s Smartest Woman (2015)

#159

Post by qot »

failwhaleshark wrote: post #99

This reminds me of the time my entire family screamed and shouted that I was wrong that buying two different lottery tickets slightly more than doubles the total (infinitesimal) odds of winning over just one. 1 in a zillion vs slightly greater than 2 in a zillion because eliminating one choice reduces the pool by one for the next choice.

But you are wrong: it's exactly double the odds.

If you bought all the tickets, do you think you'd have over 100% chance of winning?

Edit: looks like leephillips beat me to it

Re: The Time Everyone “Corrected” the World’s Smartest Woman (2015)

#160

Post by aaplok »

failwhaleshark wrote: post #99

This reminds me of the time my entire family screamed and shouted that I was wrong that buying two different lottery tickets slightly more than doubles the total (infinitesimal) odds of winning over just one. 1 in a zillion vs slightly greater than 2 in a zillion because eliminating one choice reduces the pool by one for the next choice.

I may misunderstand you, but replace the lottery with a coin toss. Buying a ticket gets you a 50% chance of winning. This reduces the pool of possible outcomes by 1 for the next choice, so there is precisely one choice left. However buying a second (different) ticket does not give you a 150% chance of winning.
Post reply on HN