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.