03-25-2004, 07:27 PM
Hi,
Yeah. The odds of one person not having a birthday on any particular day are 364.25/365.25 = 0.997262149212867898699520876112252 from my trusty windows calculator. So, the odds of all 1770 not having a birthday are simply that number raised to the 1770th power, which if I did it right is 0.0078 or about 3/4 of one percent. Small, but not negligible.
The joker is how many did not give their birthday. It would make a nice problem in a stats course to give the number of people, the number of days when no one had a birthday and then ask what percentage (most likely) of the population did not give a birth date. But there's not much we can do with just a single observation :)
--Pete
Yeah. The odds of one person not having a birthday on any particular day are 364.25/365.25 = 0.997262149212867898699520876112252 from my trusty windows calculator. So, the odds of all 1770 not having a birthday are simply that number raised to the 1770th power, which if I did it right is 0.0078 or about 3/4 of one percent. Small, but not negligible.
The joker is how many did not give their birthday. It would make a nice problem in a stats course to give the number of people, the number of days when no one had a birthday and then ask what percentage (most likely) of the population did not give a birth date. But there's not much we can do with just a single observation :)
--Pete
How big was the aquarium in Noah's ark?