Out of 25 people. More then 50% Chance that two people ....

Live forum: http://forum.freeipodguide.com/viewtopic.php?t=48135

KnightTrader

07-11-2006 19:56:42

Out of 25 people. More then 50% Chance that two people will share the same birthday. Fact...
Discuss.

TryinToGetPaid

07-11-2006 19:59:07

Ummm.....no.

I never knew anyone who had my same birthday until I came on this forum and learned I shared it with 4 or 5 different people. But if you randomly walked down the street and asked 25 people their birthday, chances are that none of them would match.

Daggoth

07-11-2006 20:00:03

Cite your source.

KnightTrader

07-11-2006 20:02:33

Trying to get paid. You are looking at it in the wrong way. You are comparing YOUR birthday with everyone elses [The 25 people]. In reality you have to compare EVERYONES birthday with EVERYONE else. Not just one persons birthday to the rest.

Source
Removed, For the sake of seeing how many people say "OMG NO YOU CANTZ DO MATH FAFSDDWAD!" I'll post source later ^^

theysayjump

07-11-2006 20:06:54

I've only met one person with the same birthday as mine, we used to work together.

GCY

07-11-2006 20:09:30

when I was in the 5th grade, 2 ppl share the exact same birthday as me. Month, day, and year. I don't know why I still remember this. ?

burritopunk

07-11-2006 20:09:41

Yeah, it's not saying that you take yourself, ask 24 other people and it will match. it's saying each of those 25 asks everyone else.

So, 25 x 25 = 625 possibilities?

Something like that.

burritopunk

07-11-2006 20:10:10

On a sidenote I have three friends from highschool that share my birthday...

Daggoth

07-11-2006 20:12:14

[quotef58c736ace="KnightTrader"]Trying to get paid. You are looking at it in the wrong way. You are comparing YOUR birthday with everyone elses [The 25 people]. In reality you have to compare EVERYONES birthday with EVERYONE else. Not just one persons birthday to the rest.

Source
Removed, For the sake of seeing how many people say "OMG NO YOU CANTZ DO MATH FAFSDDWAD!" I'll post source later ^^[/quotef58c736ace]

http//www.curiousmath.com/index.php?name=News&file=article&sid=78

Interesting how they figured it out...

justinag06

07-11-2006 20:13:23

yeah you can probably test it out. Go to users in the forum and grab a sample of like 25 random names and see if any birthday's match. Do that 10 times or so and see how many you get.

EDIT - Ok I figured it out. you simply add outs.

so you simple add up the chances of any number of people having the same birthday.


1/365 + 2/365 + 3/365 + ... n-1/365 + n/365

N = Number of people -1 or 24

(1+2+3+...n-1 + n)/365

or 300/365

to reword this lets look at me trying to get paid and knight trader.

my birthday is oct 13.

what are the odds that TGP shares the same bday as me? 1/365

what are the odds that knight trader shares the same birthday as either of us? 2/365

and so on

Akademikz

07-11-2006 20:14:30

This surely proves how stupid math is.

schizerbone

07-11-2006 20:26:59

Math isn't stupid...it works on so many levels..

gafdpc

07-11-2006 20:31:30

It's called the birthday paradox (I hope that wasnt in one of the links I didn't read).

http//en.wikipedia.org/wiki/Birthday_paradox[]http//en.wikipedia.org/wiki/Birthday_paradox

jy3

07-11-2006 22:13:31

actually wouldnt this use combination formulas and not just what you showed?
then again maybe u said that..i am tired.

mnx12

07-11-2006 22:21:11

My math teacher in like 8th grade did this. We had like 30 kids in that class, and I am pretty sure there was someone that had the same birthday as another.

corim123

08-11-2006 05:05:45

Thats pretty cool.

manOFice

08-11-2006 05:19:01

I believe i've met one person with the same birthday and a bunch with the birthday like...1 day before mine or 1 day after mine

ps....those damn live forever banners are so annoying!!

TryinToGetPaid

08-11-2006 06:25:14

Well if you clicked mine, I could take it off. -)

EatChex89

08-11-2006 09:50:14

i've known 3 people that have the same birthday as me.

tjwor

08-11-2006 10:24:53

[quote78d5fd776d="manofice"]ps....those damn live forever banners are so annoying!![/quote78d5fd776d]

Yea! but just think, If we all live forever, then you'll have even more people to share your birthday with )

doylnea

08-11-2006 10:37:35

[quoteb13f0fa1a4="corim123"]Thats pretty cool.[/quoteb13f0fa1a4]take the referral link of out your sig, or I'll give you a new sig. lol

dmorris68

08-11-2006 10:44:02

Yes, all those Live Forever! sigs have ref links in them. They all need to be removed ASAP.

Zanpaktou

08-11-2006 14:35:07

I'm actually supposed to be starting a small project on this in my AP Statistics class... we did the math at some point and it worked out... my teacher asked all fo her classes and all but mine had one or more pairs of people with the same birthday (none of the classes had more than 27 people, mine had 19 at the time we did this)... Statistically though, its true, as we all now see