Plan: move ahead on Excel – histograms, mode.

I don’t think this was a good class. I’d forgotten that I asked them (with no preparation) to offer term paper topics in their homework, so I talked about that some. Then several people asked about the T fares excel computation, so I worked it in class. Using Excel to find the absolute and relative changes was straightforward and a good review.

Then I tried to work through why you couldn’t average the relative changes to find the average relative change. I tried to explain why you needed the number of riders of each kind, to use as weights – to blank stares.

So I gave up (pretty much) and moved on to histograms. Started to build Wing Aero’s, then decided it would be better to study one first – the U.S income distribution in the exercises. So I did manage to discuss mode, and to calculate the median by keeping a running total of the buckets. But the argument trailed off when I tried working on the mean. A few students really grasped it; most were lost. So I have my work cut out for me for Thursday …

 

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