Small Solver Program

[Albert Chan]

Quadratic fit without linear algebra (32SII) - NOT only for statistics lovers - LONG

Linear regression on slope had another benefit, which my Casio cannot do.
Doing Quadratic Regression on Casio, you don't really know if it is any good.
There is no "correlation coefficient" to lookup. (Why?)

Linear regression on slope can show whether a Quadratic curve is warranted.

I think the code add slope data, like this:

Data points (0,90) and (30, 90.2), add to linear regression: (30+0)/2, (90.2-90)/(30-0)
Next point (60, 86.4), add to linear regression: (60+30)/2, (86.4-90.2)/(60-30)
...
N points (sorted) thus generate N-1 slopes to regress.