Texas Instruments PLUS TI-89 - Manual (Page 277)

260 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 260 of 22
Item Description
Freq Type the column number that contains a
“weight” value for each data point. If you do
not enter a column number, all data points are
assumed to have the same weight (
1 ).
Category Type the column number that contains a
category value for each data point.
Include
Categories If you specify a Category column, you can use
this item to limit the calculation to specified
category values. For example, if you specify
{
1,4 }, the calculation uses only data points with
a category value of 1 or 4 .
3. Press ¸ (after typing in an input box, press ¸ twice).
The results are displayed on the STAT VARS screen. The format
depends on the Calculation Type . For example:
For Calculation Type = OneVar For Calculation Type = LinReg
4. To close the STAT VARS screen, press ¸.
The Data/Matrix Editor’s Stat toolbar menu redisplays the previous
calculation results (until they are cleared from memory).
TI - 89 : 2 ‰
TI - 92 Plus: ‰
Previous results are cleared when you:
¦ Edit the data points or change the Calculation Type .
¦ Open another data variable or reopen the same data variable
(if the calculation referred to a column in a data variable). Results
are also cleared if you leave and then reopen the Data/Matrix
Editor with a data variable.
¦ Change the current folder (if the calculation referred to a list
variable in the previous folder).
The Calculate
Dialog Box
(Continued)
Note: For an example of
using Freq, Category, and
Include Categories, refer to
page 270.
Note: Any undefined data
points (shown as undef) are
ignored in a stat calculation.
Redisplaying the
STAT VARS Screen
When 6 is shown instead of =, you
can scroll for additional results.