Texas Instruments TI-83 PLUS - Manual (Page 328)

TI-83 Plus Statistics 325
To see the magnitudes of the residuals, continue with these steps.
29. Press r .
Press ~ and | to trace the data. Observe the
values for Y at each point.
With this model, the largest positive residual is
about 0.041 and the smallest negative residual
is about
L 0.027. All other residuals are less
than 0.02 in magnitude.
Now that you have a good model for the relationship between length and
period, you can use the model to predict the period for a given string
length. To predict the periods for a pendulum with string lengths of 20 cm
and 50 cm, continue with these steps.
30. Press  ~
1 to display the
VARS Y . VARS
FUNCTION
secondary menu, and then press 1 to
select 1:Y 1
. Y 1
is pasted to the home screen.