Operation Manual

Chapter 12: Statistics 202
The TI-84 Plus C uses the formula below to compute RESID list elements. The next section describes the
variable RegEQ.
RESID = Ylistname N RegEQ(Xlistname)
Automatic Regression Equation
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 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.
RegEQ found using QuickPlot & Fit-EQ are fixed 4 decimal
places.
Diagnostics Display Mode
When you execute some regression models, the TI-84 Plus C computes and stores diagnostics values for
r (correlation coefficient) and r
2
(coefficient of determination) or for R
2
(coefficient of determination).
You can control whether these values are displayed by turning
StatDiagnostics on or off on the mode
screen.
MathPrint™
Classic