12-22 Statistics
8312STAT.DOC TI-83 international English Bob Fedorisko Revised: 02/19/01 12:42 PM Printed: 02/19/01 1:37
PM Page 22 of 38
STAT CALC
menu items
3
through
C
are regression models
(page 12
.
24). The automatic residual list and automatic
regression equation features apply to all regression
models. Diagnostics display mode applies to some
regression models.
When you execute a regression model, the automatic
residual list feature computes and stores the residuals to
the list name
RESID
.
RESID
becomes an item on the
LIST NAMES
menu (Chapter 11).
The TI
-
83 uses the formula below to compute
RESID
list
elements. The next section describes the variable
RegEQ
.
RESID
=
Ylistname
N
RegEQ
(
Xlistname
)
Each regression model has an optional argument,
regequ
, for
which you can specify a
Y=
variable such as
Y
1
. Upon
execution, the regression equation is stored automatically to
the specified
Y=
variable and the
Y=
function is selected.
Regardless of whether you specify a
Y=
variable for
regequ
,
the regression equation always is stored to the TI
-
83
variable
RegEQ
, which is item
1
on the
VARS Statistics EQ
secondary menu.
Note: For the regression equation, you can use the fixed-decimal
mode setting to control the number of digits stored after the decimal
point (Chapter 1). However, limiting the number of digits to a small
number could affect the accuracy of the fit.
Regression Model Features
Regression
Model Features
Automatic
Residual List
Automatic
Regression
Equation
