Texas Instruments TI-73 EXPLORER - Manual (Page 152)

146
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 146 of 22
6. View the equation stored to
Y
1
, if desired.
&
ExpReg ExpReg - v ! 7 7
ExpReg
(exponential regression) fits the model equation
y=ab x
to the data using a least-squares fit and transformed values x
and ln(y). It displays values for
a
and
b
; when
DiagnosticOn
is
set, it also displays values for
r 2
(coefficient of determination)
and
r
(correlation coefficient). The
DiagnosticOn
command is in
the
CATALOG
(- |). You can execute
ExpReg
from the
Graph screen, the Home screen, or the Program editor.
From the Home screen or the Program editor,
ExpReg
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
L 1
and
L 2
. To access
Y
n
variables, press - }
2
.
ExpReg
[XList,YList,freq,Yn]
Graph a scatter plot for
L 1
and
L 2
, where
L 1 ={1,3,4,5,5,7,8,9}
and
L 2 ={1,4,2,3,4,6,7,9}
, and use
ExpReg
to draw the exponential
regression curve through the points.
1. Set Decimal Notation mode
to
2
, if desired.
. # " " " b
³
Y
2
, Y
3
, and Y
4
may vary.