Texas Instruments TITANIUM TI-89 - Manual (Page 566)

Statistics and Data Plots 566
In the Data/Matrix Editor, you can enter the scores and the category values in two
columns.
To use category values, specify the category column and the category values to include
in the analysis when you perform a statistical calculation or define a stat plot.
Test scores Category values
c1 c2
85 1
97 3
92 2
88 3
90 2
95 1
79 4
68 2
92 4
84 3
82 1