Texas Instruments PLUS TI-89 - Manual (Page 279)

262 Chapter 16: Statistics and Data Plots
16STATS.DOC TI-89/TI-92 Plus: Statistics and Data Plots (English) Susan Gullord Revised: 02/23/01 1:12 PM Printed: 02/23/01 2:17 PM Page 262 of 22
Calc Type Description
MedMed Median-Median — Fits the data to the model y=ax+b
(where a is the slope, and b is the y-intercept) using the
median-median line, which is part of the resistant line
technique.
Summary points medx1 , medy1 , medx2 , medy2 , medx3 ,
and medy3 are calculated and stored to variables, but
they are not displayed on the STAT VARS screen.
PowerReg Power regression — Fits the data to the model equation
y=ax b using a least-squares fit and transformed values
ln(x) and ln(y) .
QuadReg Quadratic regression — Fits the data to the second-
order polynomial
y=ax ñ +bx+c . You must have at least
three data points.
¦ For three points, the equation is a polynomial fit.
¦ For four or more points, it is a polynomial regression.
QuartReg Quartic regression — Fits the data to the fourth-order
polynomial
y=ax 4 +bx ò +cx ñ + dx+e . You must have at
least five data points.
¦ For five points, the equation is a polynomial fit.
¦ For six or more points, it is a polynomial regression.
SinReg Sinusoidal regression — Calculates the sinusoidal
regression and updates all the system statistics
variables. The output is always in radians, regardless of
the angle mode setting.
Use the applicable command for the calculation that you want to
perform. The commands have the same name as the corresponding
Calculation Type . Refer to Appendix A for information about each
command.
Important: These commands perform a statistical calculation but
do not automatically display the results. Use the ShowStat command
to show the calculation results.
Selecting the
Calculation Type
(Continued)
From the Home
Screen or a Program