Let y = sales at a fast-food outlet (1000s of $), x1 = number of competing outlets within a 1-mile radius, x2 = population within a 1-mile radius (1000s of people), and x3 be an indicator variable that equals 1 if the outlet has a drive-up window and 0 otherwise. Suppose that the true regression model is
Y = 10.00 - 1.2x1 + 6.8x2 + 15.3x3 + e
a. What is the mean value of sales when the number of competing outlets is 2, there are 8000 people within a 1-mile radius, and the outlet has a drive-up window?
b. What is the mean value of sales for an outlet without a drive-up window that has three competing outlets and 5000 people within a 1-mile radius?
c. Interpret β3.