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Student Page 3.4.5 Entering and Graphing Data and Finding Regression Equations

1.

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.

To Graph the Data:

(a)

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

(b)

Settings: On, Scatter plot (first graph), Xlist: L1, Ylsit: L2, Mark: +

(c)

Press GRAPH

3.

To Set 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.

To Fit 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, 4: LinReg(ax+b) (to fit a linear function), then Press ENTER.

(d)

Indicate the lists of the data (separated by commas for older TI-84 calculators, 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:

LinReg(ax+b)
Xlist: L1
Ylist: L2
FreqList:
Store RegEQ: Y1
Calculate

(For older TI-84s, the screen will read 4: LinReg(ax+b) L1, L2, Y1). Press ENTER (to fit a linear 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.