Re:How odd is a cluster of plane crashes?
by gus_massa on Tuesday August 18, 2015 @09:26AM
(#10079044)
The problem is not when you have much more samples than slots, in that case you should get "almost" the same number of hits in each slot as you measured.
The problem is when you get less samples than slots. For example if you roll 3 dices, you should get "1/2" hits for each result. So the question is: How probable is that one result is repeated? (i.e. you get two equal dices out of the three)
[spoiler alert]
All equal: 3%
Two equal and one different: 42%
Three different: 55%
"Intuitively", it's expected that with a uniform distribution you get something like 1% + 9% + 90% instead (this numbers are completely made up). Most people don't expect that the probability of getting a repeated dice is so close to the probability of getting all of them different.
The problem is when you get less samples than slots. For example if you roll 3 dices, you should get "1/2" hits for each result. So the question is: How probable is that one result is repeated? (i.e. you get two equal dices out of the three)
[spoiler alert]
All equal: 3%
Two equal and one different: 42%
Three different: 55%
"Intuitively", it's expected that with a uniform distribution you get something like 1% + 9% + 90% instead (this numbers are completely made up). Most people don't expect that the probability of getting a repeated dice is so close to the probability of getting all of them different.