Texas Instruments TI-73 用户手册

     Chapter 7: Statistical Analyses

7307ENG.DOC   CH 7, Statistical Analyses, English   Julie Hewlett   Revised: 07/29/98 12:07 PM   Printed: 05/19/99

9:00 AM   Page 144 of 22

5. View the line on the Graph

screen.

(

6. View the equation stored to

, if desired.

&

 

QuadReg   -

 

  v

 

  !

 

 (quadratic regression) fits the second-degree

polynomial 

 to the data. It displays values for 

, 

,

and 

; when 

 is set, it also displays a value for 

(coefficient of determination). The 

 command is in

the 

 (- |). You can execute the 

command from the Graph screen, the Home screen, or the

Program editor.
For three data points, the equation is a polynomial fit; for four

or more, it is a polynomial regression. At least three data

points are required.
From the Home screen or the Program editor, 

 accepts

four optional arguments. Enter up to two list names, XList and

YList; a frequency list, freq; and an equation variable, Yn. freq

is the frequency of occurrence for each corresponding data

point in XList and YList. If freq is omitted, all values are used

once. If XList and YList are not specified, the default list

names are 

 and 

. To access 

 variables, press - } 

.

[XList,YList,freq,Yn]

The LinReg(ax+b)  line

The Manual-Fit line, Y

 (see

example from that section)

 and Y

may vary.