For the data given in Problem 11 in Chapter 7, which concerns the relationship between the temperature (X) of a certain medium and the growth (Y) of human amniotic cells in a tissue culture, researchers wish to evaluate whether a parabolic model is more appropriate than a straight-line model. Use the accompanying computer output to answer the following questions:
a. Plot the fitted straight-line model and the fitted quadratic model on the same scatter diagram.
b. Test for the significance of adding the X2 term to the model.
c. Determine the change in R2 in going from a straight-line to a parabolic model.
d. How do your results in parts (b) and (c) compare with the results in Problem 11 in Chapter 7 for the test of adequacy of fit of the straight-line model?
e. Which model is more appropriate€”straight line or parabolic?

DEPENDENT VARIABLE.Y VARIABLE(S) ENTERED ON STEP NUMBER 1.. X MULTIPLE R R SQUARE ADJUSTED R SQUARE STANDARD ERROR MEAN SQUARE 0.98603 0.97225 0.97071 0.14263 DF SUM OF SQUARES ANALYSIS OF VARIANCE REGRESSION RESIDUAL 12.83072 0.02034 630.71608 12-83072 0.36618 18. ...........................-VARIABLES NOT IN THE EQUATON VARIABLE Xx VARIABLES IN THE EQUATION BETA IN PARTIAL TOLERANCE 0.84502 VARIABLE B. STD ERROR B BETA 0.98603 0.03582 0.00143 630.716 0.64297 0.01606 11.981 (CONSTANT) 0.46240 VARIABLE(S) ENTERED ON STEP NUMBER 2.. XX MULTIPLER R SQUARE ADJUSTED R SQUARE STANDARD ERROR 0.99183 0.98372 098181 0.11241 ANALYSIS OF VARIANCE REGRESSION RESIDUAL DF 2. 17 SUM OF SQUARES 12.98210 0.21480 MEAN SQUARE 6 49105 0.01264 513.73362 VARIABLES IN THE EQUATION VARIABLES NOT IN THE EQUATION F VARIABLE BETA IN PARTIAL TOLERANCE F STD ERROR B 0.00887 0.00006 VARIABLE 0.00537 0.00022 0.49460 BETA 0.14782 0.84502 0.367 11.981 CONSTANT) MAXIMUM STEP REACHED