12-26 Statistics
8312STAT.DOC TI-83 international English Bob Fedorisko Revised: 02/19/01 12:42 PM Printed: 02/19/01 1:37
PM Page 26 of 38
CubicReg (cubic regression) fits the third-degree
polynomial y=ax3+bx2+cx+d to the data. It displays values
for a, b, c, and d; when DiagnosticOn is set, it also displays
a value for R2. For four points, the equation is a polynomial
fit; for five or more, it is a polynomial regression. At least
four points are required.
CubicReg [Xlistname,Ylistname,freqlist,regequ]
QuartReg (quartic regression) fits the fourth-degree
polynomial y=ax4+bx3+cx2+dx+e to the data. It displays
values for a, b, c, d, and e; when DiagnosticOn is set, it also
displays a value for R2. For five points, the equation is a
polynomial fit; for six or more, it is a polynomial
regression. At least five points are required.
QuartReg [Xlistname,Ylistname,freqlist,regequ]
LinReg(a+bx) (linear regression) fits the model equation
y=a+bx to the data using a least-squares fit. It displays values
for a (y-intercept) and b (slope); when DiagnosticOn is set, it
also displays values for r2 and r.
LinReg(a+bx) [Xlistname,Ylistname,freqlist,regequ]
LnReg (logarithmic regression) fits the model equation
y=a+b ln(x) to the data using a least-squares fit and
transformed values ln(x) and y. It displays values for a and
b; when DiagnosticOn is set, it also displays values for r2
and r.
LnReg [Xlistname,Ylistname,freqlist,regequ]
ExpReg (exponential regression) fits the model equation
y=abx 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 r2 and r.
ExpReg [Xlistname,Ylistname,freqlist,regequ]
CubicReg
(ax3+bx2+cx+d)
QuartReg
(ax4+bx3+cx2+
dx+e)
LinReg
(a+bx)
LnReg
(a+b ln(x))
ExpReg
(abx)