Cooling Rates of Turbines: A multiple regression model was constructed to predict the cooling rate of a turbine given data on the number of drive shafts (SHAFTS), motor RPMs, cycle pressure ratio (CPRATIO), inlet temperature (INLETTEMP), exhaust temperature (EXHTEMP), and airflow (AIRFLOW). The regression output is below: Estimate| Std. Error t value P(>It) (Intercept) 13850 939.1 14.75 0.000SHAFTS -111.3 163.6 -.68 0.49871RPM .0913 .0144 6.32 0.000CPRATIO 8.572 32.02 .27 .79094INLETTEMP -9.293 1.512 -6.15 0.000Select all of the predictor variables which would be included in constructing the next regression model in the iteration:. 1. EXHTEMP 2. SHAFTS 3. INLETTEMP 4. AIRFLOW 5. CPRATIO RPM