So I took a 400 level statistics class in college which I did pretty well in so I understand probability somewhat. One of the topics in which we had problems on was the birthday problem, essentially what are the chances that in a group of random people, 2 of them share the same birthday (assuming all days of the year are equally weighted and counting February 29 as a possible date available every year). 2 people only have a .27% chance of sharing the same birthday (1/366) x 100%.
Up the number to 4 people and the chance of 2 of them having the same birthday is ((366 x 365 x 364 x 363)/ (4 x 366)) x 100% = 1.63%. You can see that the chance of 2 people having the same birthday is not linear as the number of random people increases. In fact, by the time you get to 41 people there is a 90% chance 2 share the same birthday and with 58 people, there is a 99% chance.
So here is a real life twist, at the engineering company I work at there are 12 employees. Of the 12, 3 pairs of people share the same birthday, though none of the common birthday pairs share the same birth year. It's even more bizarre that I share a birthday, and a first name, with a coworker who is just 1 year older than myself.
What are the chances of this? I can't quite wrap my head around the necessary "and" probability calculations. Without being able to calculate the chances, it seems that the chance of this happening randomly are damn near lottery jackpot odds.
SVTP, enlighten me with your vast math/stats knowledge :beer:
Up the number to 4 people and the chance of 2 of them having the same birthday is ((366 x 365 x 364 x 363)/ (4 x 366)) x 100% = 1.63%. You can see that the chance of 2 people having the same birthday is not linear as the number of random people increases. In fact, by the time you get to 41 people there is a 90% chance 2 share the same birthday and with 58 people, there is a 99% chance.
So here is a real life twist, at the engineering company I work at there are 12 employees. Of the 12, 3 pairs of people share the same birthday, though none of the common birthday pairs share the same birth year. It's even more bizarre that I share a birthday, and a first name, with a coworker who is just 1 year older than myself.
What are the chances of this? I can't quite wrap my head around the necessary "and" probability calculations. Without being able to calculate the chances, it seems that the chance of this happening randomly are damn near lottery jackpot odds.
SVTP, enlighten me with your vast math/stats knowledge :beer:
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