6-3-6

Calculating and Graphing Paired-Variable Statistical Data

kLinear Regression Graph

Linear regression uses the method of least squares to plot a straight line that passes close to as many data points as possible, and returns values for the slope and y-intercept (y-coordinate when x = 0) of the line.

The graphic representation of this relationship is a linear regression graph.

1(CALC)2(X)

6(DRAW)

The following is the linear regression model formula.

y = ax + b

a .............

regression coefficient (slope)

b .............

regression constant term (y-intercept)

r............. correlation coefficient

r2 ............

coefficient of determination

MSe ........

mean square error

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

#Input a positive integer for frequency data. Other types of values (decimals, etc.) cause an error.

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