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Texas Instruments TI-84 User Manual

Page 281

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Chapter 12: Statistics

278

Notice that the first three residuals are negative. They correspond to the shortest
pendulum string lengths in

L1

. The next five residuals are positive, and three of the last

four are negative. The latter correspond to the longer string lengths in

L1

. Plotting the

residuals will show this pattern more clearly.

18. Press

y ,

2

to select

2:Plot2

from the

STAT PLOTS

menu. The stat plot editor is

displayed for plot 2.

19. Press

Í to select

On

, which turns on plot 2.

Press

† Í to select " (scatter plot). Press

† y d to specify

Xlist:L1

for plot 2. Press

† ã

R

д

г

E

д

г

S

д

г

I

д

г

D

ä (alpha-lock is on) to specify

Ylist:RESID

for plot 2. Press

† Í to select ›

as the mark for each data point on the scatter plot.

20. Press

o to display the Y= editor.

Press

| to move the cursor onto the

=

sign, and

then press

Í to deselect

Y1

. Press

} Í to

turn off plot 1.

21. Press

q

9

to select

9:ZoomStat

from the

ZOOM

menu. The window variables are adjusted
automatically, and plot 2 is displayed. This is a
scatter plot of the residuals.