|
The birthday paradox, hard to believe
|
View this Thread in Original format
| hooknife |
The birthday paradox states that if there are 23 people in a room then there is a slightly more than 50:50 chance that at least two of them will have the same birthday. This means that a higher probability applies to a typical school class size of thirty, where the 'paradox' is often cited. For 60 or more people, the probability is greater than 99%. This is not a paradox in the sense of leading to a logical contradiction; it is a paradox in the sense that it is a mathematical truth that contradicts common intuition. Most people estimate that the chance is much lower than 50:50. Calculating this probability (and related ones) is the birthday problem. The mathematics behind it has been used to devise a well-known cryptographical attack named the birthday attack.
Taken from - http://en.wikipedia.org/wiki/Birthday_paradox |
|
|
| Fundamental |
I made some money off of this once. I made a bet for £20 with a friend that I could find 2 people at this house party with the same birthday. There was about 40 people there so I knew I had the odds in my favour. :D
I found 2 sets of 2, didn't get paid twice though... :p |
|
|
| hooknife |
| quote: | Originally posted by Fundamental
I made some money off of this once. I made a bet for £20 with a friend that I could find 2 people at this house party with the same birthday. There was about 40 people there so I knew I had the odds in my favour. :D
I found 2 sets of 2, didn't get paid twice though... :p |
hmmmmmm......thats a damn good idea, I'll have to try that one. |
|
|
| jonze234 |
| statistics professors love to do that in their classes. |
|
|
| M@t |
bumpety click
for research's sake |
|
|
| Inertia |
i do find that hard to believe. in a school of 400+, i'm the only one with my birthday.
the only other people i know of with my same bday (feb 12) are abe lincoln, this dude i recently met, and the mother of one of my friends. |
|
|
| hooknife |
| quote: | Originally posted by Inertia
i do find that hard to believe. in a school of 400+, i'm the only one with my birthday. |
That is not the normal, obviously. |
|
|
| Resnick |
| quote: | Originally posted by hooknife
That is not the normal, obviously. |
actually it is...theres a difference between someone having ur birthday and any 2 ppl having the same birthday
statistically tehre should be 1 other person in ur school that has ur bday (in 400 ppl) |
|
|
| milanster |
| yup...took that in my probability class in univ 3 yrs ago....damn interesting ;) |
|
|
| kutvolkots |
| Less people rememeber their condoms in spring it's that simple. |
|
|
| Floorfiller |
| that's pretty crazy...i never would think that would be true.... |
|
|
| butterfly |
| arent some birthdays more common than others? if that is the case, is it considered in calculating the statiscal probability? |
|
|
|
|
