It is President’s Day on Monday. That got me to thinking about Washington and Lincoln. Stanczyk, has had an awful lot of mathematical training – the product of a degree from a School of Engineering. It is funny, the teachings that stick with you your whole life. One of the things that I learned that stuck with me was a little factoid from a Probability & Statistics course. I was taught that in a gathering of just of 19 people that the probability that two of them having the same day of birth (not the same year though) would be 50-50. That in any gathering of 19 people it would be a 50% chance of two people celebrating their birthday on the same day each year!
This being President’s Day weekend, I noted that we have had 44Presidents (only 43 different, since Grover Cleveland was the 22nd and the 24th President). So I asked myself did any two Presidents have the same day of birth? Now if we ignore the Grover Cleveland issue, and we examine the dates of birth of all US Presidents, we do indeed find that two Presidents had the same day of birth. The day in calendar is November 2nd. The two Presidents who share that day are: Warren G. Harding and James K Polk.
Now you might expect that since we have > 38 Presidents, that there should be two pairs of matches. But the odds are only 50-50. So we have just one matching pair of Presidents. There were a lot of near misses (off by one day). If your birth month is not September or June (each of which only had one President) then the odds are pretty good that you, my dear reader, share a birth day with one of the Presidents. I’d say better than 50-50. So click on the link and see for yourself.
Happy President’s Day!