Let y = sales at a fast-food outlet (1000s of $), x1 = number of competing outlets withi...

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

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.