Increasing customer satisfaction typically results in increased purchase behavior. For many products, there is more than one measure of customer satisfaction. In many, purchase behavior can increase dramatically with an increase in just one of the customer satisfaction measures. Gunst and Barry ("One Way to Moderate Ceiling Effects," Quality Progress, October 2003, pp. 83-85) consider a product with two satisfaction measures, X1, and X2, that range from the lowest level of satisfaction, 1, to the highest level of satisfaction, 7. The dependent variable, Y, is a measure of purchase behavior, with the highest value generating the most sales. Consider the regression equation:

Suppose that X, is the perceived quality of the product and X2 is the perceived value of the product.
a. What is the predicted purchase behavior when X1, = 2 and X2 = 2?
b. What is the predicted purchase behavior when X1, = 2 and X2 = 7?
c. What is the predicted purchase behavior when X1, = 7 and X2 = 2?
d. What is the predicted purchase behavior when X1, = 7 and X2 = 7?
e. What is the regression equation when X2 = 2? What is the slope for X1, now?
f. What is the regression equation when X2 = 7? What is the slope for X1, now?
g. What is the regression equation when X1, = 2? What is the slope for X2 now?
h. What is the regression equation when X1, = 7? What is the slope for X2 now?
i. Discuss the implications of (a) through (h) in the context of increasing sales for this product with two customer satisfaction measures.