Home > Statistics Every Writer Should Know > The Stats Board > Discusssion
birthdays
Message posted by mike on June 4, 2000 at 12:00 AM (ET)
in a room of 30 people, what are the chances of two people having the same birthday
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(In chronological order. Most recent at the bottom.)
Re: birthdays
Message posted by Phil on June 6, 2000 at 12:00 AM (ET)
The probability that two or more people have birthdays on the same day is 1 -(probability that no people have the same birthday). That is 1 - (364/365)*(363/365)*...*(336/365)= 1 - 0.294 = 0.706
Re: birthdays
Message posted by Scott Baber on June 19, 2000 at 12:00 AM (ET)
I think your wrong no offence but i went on a chat site and i found a couple of people with the same birthday as me bye bye
Re: birthdays
Message posted by Phil on June 22, 2000 at 12:00 AM (ET)
Why was I wrong? In a group of thirty people there is a 70.6% chance of finding at least one pair with the same birthday. By the way. This is a random event. Probabilities and actual outcomes should agree over the long run, not with just one sample.
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