Measures of Variation

Examples of measure of variation (measures of the spread of data), with a focus on computing and understanding standard deviation. I threw in z-scores as well to help explain why we would bother computing a standard deviation. I can't explain why you watch this horribly boring video all the way to the end to see it, though.
If you were looking for Chebyshev's theorem or the empirical rule, you'll have to go to the class PowerPoints (I have a KZbin playlist for those, too, and you might prefer those anyway since you won't have to hear me talk).