7-5-5

Graphing Paired-Variable Statistical Data

Drawing a Linear Regression Graph

Linear regression uses the method of least squares to determine the equation that best fits your data points, and returns values for the slope and y-intercept. The graphic representation of this relationship is a linear regression graph.

u ClassPad Operation

Start the graphing operation from the Statistics application’s Graph window or List window.

From the Graph window

Tap [Calc] [Linear Reg] [OK] [OK] ".

From the List window

Tap [SetGraph] [Setting…], or G.

On the Set StatGraphs dialog box that appears, configure a StatGraph setup with the setting shown below, and then tap [Set].

Type: LinearR

Tap yto draw the graph.

The following is the linear regression model formula. y = a·x + b

a : regression coefficient (slope)

b : regression constant term (y-intercept)

r : correlation coefficient

r2 : coefficient of determination

MSe : mean square error

 

1

 

n

• MSe =

 

Σ (yi – (a·xi+ b))2

n –

2

 

i=1

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