A fast food restaurant chain is interested in modeling the mean weekly sales of a restaurant, E(y), as a function of the weekly traffic flow on the

A fast food restaurant chain is interested in modeling the mean weekly sales of a restaurant, E(y), as a function of the weekly traffic flow on the street where the restaurant is located and the city in which the restaurant is located. The table contains data that were located on 24 restaurants in four cities. The model that has been proposed is