Texas Instruments TI-84 PLUS SILV Guidebook - Page 188

16. Press y 9 to display the LIST NAMES menu. If necessary, press † to move the cursor onto the list name RESID. 17. Press Í to select RESID and paste it to the stat list editor's Name= prompt. 18. Press Í. RESID is stored in column 3 of the stat list editor. Press † repeatedly to examine the residuals. 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. 19. Press y , 2 to select 2:Plot2 from the STAT PLOTS menu. The stat plot editor is displayed for plot 2. 20. 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 † ãRä ãEä ãSä ãIä ãDä (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. 21. 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. 22. 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. Chapter 12: Statistics 181