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Monday, June 2, 2008

What's so special about 1st June

We get a "Happy Birthday" email in our company everyday wishing the Birthday boys & girls, obviously, on their B'day. And?
Well, I check the email everyday to see if I it is the B'day of anyone I know. And what do I see on June 1st. It happens to be a Birthday for 14 people in our organisation out of 969 people!
Why should that sound strange? It is if you see the probability of that happening?
What does law of averages tell us? That given a sufficiently large set of people, you will have almost equal number of people being born on any given day. Well, 969 is not a sufficiently large set but we can take an error of 30% here or there(let's not get into the standard deviation mess. Not everyone has a stomach for it). Ok, so with the above theory having set in, it is likely that 969/365=2.65 people will have their birthday on any given day. With an error of 30% 1.85 - 3.44 is the range of people who'll have their birthday on any given day.
Now, do you see the anamoly here? Now, either September 1st has some fertile aspect about it that we don't know of or it is our schools who's playing truant with our probabilities. Schools? Yes schools. The schools in India, almost everywhere, reopen after a 2-3 month holiday on 1st June. And unscrupulous schools and enthusiastic new parents combine to make a lot of children's B'day 1st of June so that the child is perfectly placed for admission.
Fortunately, though, you will not see this phenomenon when the rigged-birthday workforce retire. The government is strict about Birth certificates now and the schools require them without fail. So, I am hoping that our probabilities will be restored soon :)