Using Your TI for Regression

Regression allows you to find a curve that best fits a set of data. Regression is a major feature of MTH 110 and is also used in MTH 122, 123, and other classes. Click here for doing regression with multiple data sets!

On the 82, 83, and 84:

To graph the scatter plot:
STAT    Edit    {enter data}    STATPLOT    PLOT1 ON    ENTER    Zoom    9:ZoomStat

To compute the regression coefficients:
STAT    CALC    {select regression type}    ENTER

To graph the regression line:
Y=    VARS    Statistics    EQ    RegEQ    GRAPH

To use the linear regression for prediction, the equation is in Y=

On the 85:

To graph the scatter plot:
STAT    EDIT    {two down arrows}    CLRxy    {enter data} {set your window to an appropriate size}    STAT    DRAW    SCAT

To compute the regression coefficients:
STAT    CALC    {two down arrows}    {select regression type}

To graph the regression line:
GRAPH    y(x)=    STAT    VARS    RegEq

To use the regression for prediction:
STAT    FCST    or use the equation in y=

On the 86:

To graph the scatter plot:
STAT    EDIT    {enter data including 1s in fStat}    EXIT    STAT    PLOT    PLOT1    {choose type and mark}    GRAPH    ZOOM    ZDATA

To compute the regression coefficients:
STAT    CALC    {select regression type}

To graph the regression line:
GRAPH    y(x)=   STAT    VARS    RegEQ

To use the regression for prediction:
STAT    FCST    or use the equation in y=

On the TI-89, TI-92, and the Voyage 200

You can enter this program yourself, or drop by A-2-168 Mackinac Hall to have it transferred directly to your calculator.

Note: for -> use the Store key.

Syntax: regress( {list of x coordinates separated by commas}, {list of y coordinates separated by commas} )

Program

regress(t,u)
Prgm

ClrIO

t->L1
u->L2
ClrDraw
PlotsOff
FnOff
NewPlot   1,1,L1,L2
ZoomData
Pause

Dialog
    Title "CHOOSE REGRESSION TYPE"
    DropDown "Fit a",{"line","quad","cubic","quart","power","exp","ln","sin"},w
EndDlog

If w=1 Then
    LinReg L1,L2
EndIf
If w=2 Then
    QuadReg L1,L2
EndIf
If w=3 Then
    CubicReg L1,L2
EndIf
If w=4 Then
    QuartReg L1,L2
EndIf
If w=5 Then
    PowerReg L1,L2
EndIf
If w=6 Then
    ExpReg L1,L2
EndIf
If w=7 Then
    LnReg L1,L2
EndIf
If w=8 Then
    SinReg L1,L2
EndIf

ShowStat
regeq(x)->y1(x)
DispG

EndPrgm

Regression with Multiple Lists on the 82, 83, and 84:

If there are two sets of data that we wish to compare, L1 and L2 can be used for the one set of data; L3 and L4 can be used for the other set of data.

To graph the scatter plot:
STAT     Edit    {enter data in L1 through L4}     STATPLOT
PLOT1     ON     L1     L2     ENTER
PLOT2     ON     L3     L4     {Choose different mark than Plot1}     ENTER
Zoom    9:ZoomStat

To compute the regression coefficients:
STAT     CALC     {select regression type}     ENTER
Y=     VARS     Statistics     EQ     RegEQ     GRAPH
STAT     CALC     {select regression type}     L3, L4     ENTER
Y=     {Put cursor in Y2}     VARS     Statistics     EQ     RegEQ     GRAPH

To use the linear regression for prediction, the equations are in Y=