Probability question

0 votes

5050/50 for 101?

i go with 100

(100*49 + 150) / 50 = 101
had to think for like 15 seconds, what came first to mind was "it's still 100".

hm we are talking about a "mean iq" that implies that there a higher and lower iqs, just because we happen to pick a higher iq first shouldnt change the mean iq, that how i see it.. thank god im not a poker player, given that everbody is saying 101

On March 22 2011 07:20 ERASA wrote: hm we are talking about a "mean iq" that implies that there a higher and lower iqs, just because we happen to pick a higher iq first shouldnt change the mean iq, that how i see it.. thank god im not a poker player, given that everbody is saying 101

the mean iq is by definition 100 for the entire population, that doesnt mean it's 100 for every sample. If we were defining the mean iq of those 50 children as 100 then we wouldnt be able to say what iq the first child tested has before we tested everyone (or the first one tested would always have an iq of 100 as he's the entire tested population at that point).

I think your first assumption is wrong, the expected IQ for every sample should be 100. The only real question is, can you isolate the one person in that sample like you did or is the 150 just part of the sample that happens to be brighter than the average, like i did.

erasa the problem is that knowing one member of the sample does not justify conclusions about the others.

For example, let's say you play 1000 hands of poker, with the EV of getting aces 5 times. If you hit 4 of them during the first 100 hands, you can't conclude that "ok, I'll probably get aces only once during the next 900 hands". Instead the ev becomes 4 + (EV of the amount of aces gotten during 900 hands)

You guys a probably right, thats why i stick to 10$ SnGs :D

On March 22 2011 07:38 ERASA wrote: I think your first assumption is wrong, the expected IQ for every sample should be 100. The only real question is, can you isolate the one person in that sample like you did or is the 150 just part of the sample that happens to be brighter than the average, like i did.

I think you missread my post. That the expected IQ is 100 doesnt mean it's always 100. If we get all-in on a coinflip my ev is 50% of the pot, that doesnt mean we chop the pot every time. Knowing the iq of one of the children is like knowing one of the cards of the board runout.

On March 22 2011 07:16 Oskar_123 wrote: (100*49 + 150) / 50 = 101 had to think for like 15 seconds, what came first to mind was "it's still 100".

went through the exact same thinking proccess


good article btw

Idioms such as "errors cancel each other out" reflect the image of an active self-correcting process

why most of us thought its still 100

150x50, 7500 obviously. Next question

150 is indeed a pretty mean IQ

sick city with an infinite number of eight graders?

mean means average , so the highest and lowest are irrelivant

the ultimate answer is
+ Show Spoiler +

off top of my head...100
same as saying you flip a coin 9 times and it's heads, what is the chance of it being heads on the 10th: the same as it's average..or something like that, no?

In theory it should be a 100, you could ask the same question and replace 150 with 102 the answer will still be a 100( In theory!)

Same about flipping the coin. You can toss it 50 times and it could be 50 times tales, the 51th time the odds will still be 50-50

101.
You picked one with 150. Now you are to pick 99 from a sample with mean 100.

101
You estimate the average of the IQ's you don't know to be 100, add the 150 and divide by 50 (49*100+150)/50

But that was already posted so my bad