Chapter 12: Statistics 276
Since the scatter plot of time-versus-length data appears to be approximately linear, fit a
line to the data.
10. Press … ~ 4 to select 4:LinReg(ax+b) (linear
regression model) from the STATCALC menu.
LinReg(ax+b) is pasted to the home screen.
11. Press y d ¢ y e ¢. Press ~ 1 to
display the VARS Y-VARS FUNCTION secondary
menu, and then press 1 to select 1:Y1. L1, L2, and
Y1 are pasted to the home screen as arguments to
LinReg(ax+b).
12. Press Í to execute LinReg(ax+b). The linear
regression for the data in L1 and L2 is calculated.
Value s for a and b are displayed on the home
screen. The linear regression equation is stored in
Y1. Residuals are calculated and stored
automatically in the list name RESID, which
becomes an item on the LISTNAMES menu.
13. Press s. The regression line and the scatter
plot are displayed.