A Probability Question (Humans)

by David Turell , Sunday, July 31, 2011, 15:12 (4660 days ago) @ xeno6696


> > I would guess 1 in 24
> 
> Well, you're the only one who's interested, so I'll go ahead and explain the results. 
> 
> The answer is a Probability P(.70) or 70%. If you have 23 people, it's P(.5) and at 57 you reach P(.99) or 99%.
> 
> Why so high? There's 365 days of the year, right? so assuming all birthdays are equal, the probability would intuitively be 1/365 * 1/365. (A basic rule in probability is that the probability of two events ocurring is the probability of both events, multiplied.) But that only supplies part of the model. -My answer came from relating 30 people and 360 days equals a probability of 12. Since it required 2 people, therefore 24. This is the amazing level of my math ability. I do remember something about chi square. Matt, it is ok if you chortle.