Texas Instruments TITANIUM TI-89 - Manual (Page 546)

Statistics and Data Plots 546
Selecting the Calculation Type Selecting the Calculation Type Selecting the Calculation Type Selecting the Calculation Type
From the Calculate dialog box ( ‡), highlight the current setting for the
Calculation Type
and press B.
You can then select from a menu of available
types.
Calc Type Description
OneVar One-variable statistics — Calculates the statistical variables.
TwoVar Two-variable statistics — Calculates the statistical variables.
CubicReg Cubic regression — Fits the data to the third-order
polynomial y=ax
3
+bx
2
+cx+d. You must have at least four
data points.
• For four points, the equation is a polynomial fit.
• For five or more points, it is a polynomial regression.
ExpReg Exponential regression — Fits the data to the model
equation y=ab
x
(where a is the y-intercept) using a least-
squares fit and transformed values x and ln(y).
If an item is dimmed,
it is not valid for the
current Calculation
Type.