12–22 Statistics
82D315~1.DOC TI-83 international English Bob Fedorisko Revised: 10/26/05 1:36 PM Printed: 10/27/05 2:53
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-82 STATS 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 Y1. 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-82 STATS
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