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Class #8

Cents and the Central Limit Theorem

Read the New York Times article "Opportunity Presents Itself: Kill the Penny." What is the average age of a penny in circulation?

The article quotes Philip N. Diehl, director of the mint, as saying: "Two-thirds of the pennies produced in the last 30 years have dropped out of circulation." How would you our data to check this estimate?

Here are the ages of the pennies in our class sample (A 2000 penny is one year old, a 1999 is two years old, etc.).

Here are the number of pennies (in billions) minted in each year. (*2000 data were only through January of last year.

Click for a tab-delimited text file of our data.

Amusing visualization of the number of pennies in circulation.