Thursday, December 10, 2009

And now for something completely different

You have entered 131,155 Bills worth $346,299
Bills with hits: 9,205 Total hits: 10,419
Hit rate: 7.02% Slugging Percentage: 7.94% (total hits/total bills)
George Score: 1,268.43
Your rank (based on George Score) is #199
(out of 49,660 current users with a George Score. [99.6 Percentile])
Your State Rank in Florida is: 19 out of 7,924 [99.8]
Your initial entries with hits have traveled a total of 4,879,028 miles.
They have averaged 474.9 miles per hit and 194.41 days between each hit.

For those of you that think that math has no real-world application, I present to you a case of statistical sampling. Very often, I will enter 100 or more bills at a time. Once in a while, I’ll have entered fewer bills than I should have. This means one of two things: either I was shorted a bill or I missed one.

Since I deal with banks and casinos, I’m dealing with people that are a bit paranoid about money and thus not likely to short me a bill. When I’m missing a bill like that, it means that I’ve skipped over one. You may ask how I can find one missing bill among 100, 200, 300 or more. Do I have to go through each bill?

I used to do that until I realized that I didn’t have to. That’s where statistical sampling comes in. Let’s say that I have 250 bills. I think I’ve entered all of them only to discover that I’ve actually entered 249. I count off 10 bills at a time and check the top bill against the recently entered bills.

The top bill on my pile should be the most recently entered bill. If I count off ten bills, the next should be the eleventh most recently entered. When I find one that doesn’t match, I’ve effectively narrowed it down to a range of ten bills; my missing bill should be in there. (If it’s not, I’ve probably miscounted.)

I know this may well be boring to most, but it is an example of how paying attention in math class can help.

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