In an attempt to quantify the effect of temperature and pressure on the yield obtained from a laboratory scale catalytic process, the data shown in Table 16.7 was obtained from a series of designed experiments where temperature was varied over a relatively narrow range, from 85^oC to 100^oC, and pressure from 1.25 atmospheres to 2 atmospheres. If Yield is y, Temperature is x1 and Pressure, x2, obtain a regression model of the type in Eq (16.135) and evaluate the model ?t.