What way of calculating ROI makes it easiest to compare investments?

The cook corporation has two divisions--east and west. the divisions have the following revenues and expenses: east west sales $ 603,000 $ 506,000 variable costs 231,000 300,000 traceable fixed costs 151,500 192,000 allocated common corporate costs 128,600 156,000 net operating income (loss) $ 91,900 $ (142,000 ) the management of cook is considering the elimination of the west division. if the west division were eliminated, its traceable fixed costs could be avoided. total common corporate costs would be unaffected by this decision. given these data, the elimination of the west division would result in an overall company net operating income (loss)