Casio fx-CG20 kMed-MedGraph, kQuadratic/Cubic/Quartic Regression Graph, y = ax + b, y = ax2 + bx + c, Cubic regression, Quartic regression, Quadratic regression

kMed-Med Graph

When it is suspected that there are a number of extreme values, a Med-Med graph can be used in place of the least squares method. This is similar to linear regression, but it minimizes the effects of extreme values.

1(CALC)3(Med)

6(DRAW)

The following is the Med-Med graph model formula.

y = ax + b

a..............	Med-Med graph slope
b..............	Med-Med graph y-intercept

kQuadratic/Cubic/Quartic Regression Graph

A quadratic/cubic/quartic regression graph represents connection of the data points of a scatter diagram. It uses the method of least squares to draw a curve that passes close to as many data points as possible. The formula that represents this is quadratic/cubic/quartic regression.

Ex. Quadratic regression

1(CALC)4(X2)

6(DRAW)

Quadratic regression

Model formula.......		y = ax2 + bx + c
a..........	regression second coefficient
b..........	regression first coefficient
c..........	regression constant term
	(y-intercept)

Quartic regression

Cubic regression

Model formula....... y = ax3 + bx2 + cx + d

a.......... regression third coefficient

b.......... regression second coefficient

c.......... regression first coefficient

d.......... regression constant term

(y-intercept)

Model formula....... y = ax4 + bx3 + cx2 + dx + e

a.......... regression fourth coefficient

b.......... regression third coefficient

c.......... regression second coefficient

d.......... regression first coefficient

e.......... regression constant term (y-intercept)

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