With the addition of five pairs of observations€”(18,000, 39.2), (22,400, 27.9), (24,210, 22.3), (5,400, 11.7), and (9,340, 32.5)€”to the data in Problem 3 in Chapter 5, the accompanying computer output is obtained for the regression of TIME (Y) on INC (X).
a. Using the accompanying computer output, complete the following ANOVA table for the straight-line regression of TIME (Y) on INC (X).

b. Using the accompanying computer output, complete the following ANOVA table for the quadratic regression of TIME (Y) on INC (X).

c. On the scatter diagram of the data for this problem, plot the fitted straight-line (degree 1) equation and the fitted quadratic (degree 2) equation.
d. Calculate and compare the R2-values obtained for the straight-line, quadratic, and cubic fits.
e. Carry out F tests for the significance of the straight-line regression and for the adequacy of fit of the straight-line model.
f. Carry out F tests for the significance of the quadratic regression, of the addition of the quadratic term to the model, and of the adequacy of fit of the quadratic model.
g. Which model is most appropriate: straight-line, quadratic, or cubic?
Linear regression of TIME (Y) on INC (X)

Quadratic regression of TIME (Y) on INC (X)

Cubic regression of TIME (Y) on INC (X)

Regression of TIME (Y) on INC (X)

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Source d.f. MS Regression Residual Lack of fit 18 Pure error Total 24 Source d.F MS Degree I (X) Regression Degree 2(x|X) Residual Lack of fit ResidualPure ertror 17 Total 24 PARAMETER ESTIMATES Parameter Standard Error Variable DF Estimate t ValuePr>[! Intercept 20.17655 4.60655 4.38 00002 1 000061197 0.00030000 204 00530 PARAMETER ESTIMATES Parameter Estimate Standard Variable DF Error 3.90293672-5,09 <,0001 0.00064060 12.29 <.0001 0,00000002 11.52<0001 tValue | Pr> 19.86602 0.00787 10.00000025 Intercept X2 PARAMETER ESTIMATES Parameter Estimate Standard Variable DF t Value Pr>It 35.292777 0.012227 0.00000059 Error 8.14734679 -4 0.00214424 5.70 $0001 0.00000016 366 0.0015 Intercept 4.33 0.0003 x2 17.807105-1200000 11 0466 X3 2.11 0.0466 Portion of output omitted) Type 1 Sum of Squares Regression Linear Quadratic Cubic DF 442.914529 2100.080668 61.100193 Sum of Residual Lack of Fit Pure Error DF Squares Mean Square 16 271.748723 16.984300 5 15.201250 3.040250