242 calculus and probability distributions together

In my preparation for class on February 4, I was seeking a standard deviation for age at death. (See page 381 for the problem that got me started.) It's not a normally distributed variable, though, so what I had in mind would not be valid. Hoewever, what I did find is very interesting, if you like calculus and curve-fitting: click here. The curve fitting in the TI-83 is a gas: here's how.