Cooling method for gas turbines. 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 12.27

(p. 701). Recall that you fitted a first-order model for heat rate (y) as a function of speed 1x12, inlet temperature 1x22, exhaust temperature 1x32, cycle pressure ratio 1x42, and air mass flow rate 1x52.

A MINITAB printout with both a 95% confidence interval for E(y) and a prediction interval for y, for selected values of the x’s, is shown above.

a. Interpret the 95% prediction interval for y in the words of the problem.

b. Interpret the 95% confidence interval for E(y) in the words of the problem.

c. Will the confidence interval for E(y) always be narrower than the prediction interval for y? Explain.

Transcribed Image Text:

MIMITAB output for Exercise 12.37 Predicted Values for New Observations Neu Obs 1 12632.5 Fit SE Fit 237.3 95% CI 95% PI (12157.9, 13107.1) (11599.6, 13665.5) Values of Predictors for New Observations RPM INLET-TEMP EXH-TEMP CPRATIO Neu Obs 1 7500 1000 525 AIRFLOW 13.5 10.0