Refer to the Journal of Engineering for Gas Turbines and Power (Jan. 2005) study of a high-pressure inlet fogging method for a gas turbine engine, presented in Exercise. Consider a model for the heat rate (kilojoules per kilo-watt per hour) produced by a gas turbine as a function of cycle speed (revolutions per minute) and cycle pressure ratio. The data are saved in the GASTURBINE file.
a. Write a complete second-order model for heat rate (y).
b. Give the null and alternative hypotheses for determining whether the curvature terms in the complete second-order model are statistically useful in predicting the heat rate (y).
c. For the test in part b, identify the complete and reduced models.
d. Portions of the MINITAB printouts for the two models are shown below. Find the values of SSER, SSEC, and MSEC on the printouts.
e. Compute the value of the test statistics for the test of part b .
f. Find the rejection region for the test of part b. Use α = .10.
g. State the conclusion of the test in the words of the problem.