From experience I'd guess around 20% or so, no way to seriously calculate that, but no matter what it exactly is, just want to be clear having a special weird connection means nothing (though it is fun).Then, something the other didn't take into account, looking at birth rates per month we get a nice overview (it's caused by things like people being off thus having a lot of free time on hand 9 months before the months in question), next dividing that percentage by the number of days in that month.

Even third or fourth year math majors will struggle a bit with the “true” probabilities behind why this works.

Figuring out same birthday odds is very complex for many reasons including: Figuring out the true probabilities involves Bayesian logic; hop over to this Stanford University page for a more detailed explanation on Bayesian logic and same birthday odds.

Twenty nine of us meeting someone with the same birthday: 1/12.

Those are pretty good odds, but not high enough to account for all those coincidences. The odds are actually much higher (over 100 percent for a class of 30).

Same Birthday Odds It stands to reason that same birthday odds for one person meeting another are 1/365 (365 days in the year and your birthday is on one of them).

But consider this: If you get a group of 30 people together, two of them will almost definitely have the same birthday. There were 30 students in my undergrad statistics class and the professor said the odds of two of us having the same birthday were very high. We’re talking about every student having those odds.Two people have a 1/183 chance of meeting someone with the same birthday. Those two people might also have the same birthday, right, so you have to add odds of 1/365 for that.The odds become 1/365 1/182.5 = 0.008, or .8 percent.I know that the chances of meeting someone who was born on the same date than me is fairly high and I know a few people with whom I share my birthday although for the little I've read about the birthday paradox, it doesn't take same year into account.We've argued before about the probabilities and I am still not satisfied.------------------------------------------------------------------------------ Need help with a homework or test question?

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