Friday, August 29, 2008

I can't Believe he Wore that Shirt

Thursday night I went to the Lift (the big Vineyards young adult service). This is not unusual, I go every week. What is unusual is that when I walked in my brother started laughing at me. He flagged me over to him and pointed somethig very strange out to me. The guy sitting across from him was wearing the exact same shirt as me. Now, if I had been wearing a sports shirt, or perhaps an Old Navy special this wouldn't have been quite as shocking. That, however, was not the case. I was wearing a vintage, yellow, 1980's shirt that says I'm Ship Shape Royal Caribbean. Seriously, what are the chances of that? No, I'm serious what are the chances. Lets do the math.

There are 301,000,000 people in the US.
Lets estimate that there were 100,000 of this particular shirt made, just a guess.
Of those 100,000 lets assume that over the last 20 years 75% of them were destroyed.
That leaves 25,000 shirts.
The Lift normally has around 200 people in attendance.
Let's also assume that each of them owns at least 20 shirts. That's an average since I own well over 100.

Ok so here comes the math. .0000664451827242525% of the US population was in that room. .008305647840531562% of the people in the US own that particular shirt. The chances of one person who owns that shirt choosing to wear it on any given night is 5%. The chances of two people who own that shirt picking it on the same night is .25%. Anyhow, here is the mathematical formula that I came up with. Correct my math if I'm wrong because I probably am.

25,000/301,000,000 * 200 *.25 = 0.0041528239202657807308970099667774% or 1 in 24,080



snobound said...

Did you at least talk to the guy afterward and find out what his story was? Perhaps he bought if off of Ebay one night while watching The Poseidon Adventure. Or, maybe the guy just likes lemon yellow. Or what about this, instead of turning it into a mathematical nightmare, maybe the guy just has really good taste....huh?, huh?, did ya ever think of that one??? It could be his favorite shirt and he might wear it everywhere he goes. Anything's possible right, mate? :)

DanThoms said...

I did talk to him. He bought the shirt at a thrift store in California. He is going to UC to be a pharmacist. Pharmacist apparently make over $100,000 a year.

Anonymous said...

I checked your math and your formula should have been written as:


That changes it to about a 1 in 3 chance that that guy would be wearing your shirt. So it's really not that big a deal!

Anonymous said...

The fun thing about coincidence is this:

Although a certain event might seem eerily uncanny or unlikely (and statistically, is very unlikely), the probability of something (though not any one thing in particular) happening that seems uncanny or unlikely is actually quite high.

Take your example, the yellow shirt. Odds are heavily in favor of you two not wearing the same shirt, which makes the coincidence seem odd. BUT, think about this: How many things could have happened at that particular time that you would have considered odd?

He wore the exact same uncommon shirt, but what if you were both wearing the exact same uncommon hat or weird shoes or you both decided to bring a harmonica with you or you both have the same favorite 9 letter word, etc.

While any single occurrence above would have a very low probability, if you add together all of the things that would seem errily coincedental together, the probability of one of them happening becomes palatably high.

DanThoms said...

Thats so very true. When there are an infinite amount of possibilities, the chances of one of them happening is quite good even when the chances of any single one happening is quite unlikely.