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Student Page 4.4.4 Entering, Graphing, and Plotting Data: Finding Regression Equations
A4US

1. Entering the Data.

Use your graphing calculator to enter the data:

(a)

Press STAT then choose 1: Edit…

(b)

Enter the values for the independent variable (domain) into L1.

(c)

Enter the values for the dependent variable (range) into L2.

2. Graphing the Data.

(a)

Press STAT PLOT (2ND Y=) then choose 1: Plot1… Press ENTER

(b)

Settings:

  • On,

  • Scatter plot (first graph type)

  • Xlist: L1

  • Ylist: L2

  • Mark: +

(c)

Press GRAPH

3. Setting the Viewing Window.

(a)

Press WINDOW

(b)

Use the table to determine

Xmin, Xmax, Xscl

Ymin, Ymax, Yscl

(c)

OR Press ZOOM then scroll down to 9: ZoomStat, Press ENTER

4. Fitting a Function to the Data.

(a)

Press STAT

(b)

Move the cursor to the right to highlight CALC

(c)

Scroll down to the function type you want to use, for example, 5: QuadReg, then Press ENTER (to fit a quadratic function)

(d)

Indicate the lists of the data separated by commas, for example, L1, L2.

(e)

Choose where you want to place the function equation, for example, Y1. Press VARS, move the cursor to the right to highlight Y-VARS, Press ENTER to choose 1: Function, scroll to highlight the Y-variable you want, then press ENTER again.

(f)

The screen should read: 5: QuadReg L1, L2, Y1. Press ENTER (to fit a quadratic function)

(g)

The regression equation will be in Y1 or whatever Y-variable you chose.

(h)

Press GRAPH to plot the regression equation with the data.