A chemical engineer is investigating how the amount of conve

A chemical engineer is investigating how the amount of conversion of a product from a raw material (y) depends on reaction temperature (x1) and the reaction time (x2). He has developed the following regression models:

(a) What is the predicted value of conversion when x2=2? Repeat this calculation for x2=8. Draw a graph of the predicted values for both conversion models. Comment on the effect of the interaction term in model 2.

(b) Find the expected change in the mean conversion for a unit change in temperature x1 for model 1 when x2=5. Does this quantity depend on the specific value of reaciton time selected? why?

(c) Find the expected change in the mean conversion for a unit change in temperature x1 for model 1 when x2=5. Does this quantity depend on the specific value of reaction time selected? Why?

Solution