To overlay the regression line and the scatter diagram for the data, you must
first set up the scatter diagram by pressing 2ndF STAT PLOT , touching
A PLOT1, pressing ENTER ENTER ENTER 2ndF L1 ENTER
2ndF L2 ENTER 2ndF STAT PLOT , touching G S.D., and double touching
3 Scattr.
Display the scatter diagram for the data by pressing WINDOW and setting
Xmin = 10, Xmax = 30, Xscl = 5, Ymin = 15, Ymax = 40, and Yscl = 5. Press Y=
CL to clear any previously entered expressions. Press GRAPH to view the
scatter diagram.
To view the overlay of the regression line and the scatter diagram, press Y=
VARS , touch H STAT, press ENTER , touch B REGEQN, double touch
1 RegEqn, and press GRAPH . The following overlay will be displayed.
For Discussion
You and your students can discuss:
1. In what pattern would the data points lie to form a coefficient
of correlation of zero?
2. Engage the trace and pressing or and using the
regression line to make a prediction.
42 Linear Regressions/STATISTICSUSING THE SHARP EL-9600