Vance Asbestos Removal Company removes potentially toxic asbestos insulation and related products from buildings. The company$$s estimator has been involved in a long$-$simmering dispute with the on$-$site work supervisors. The on$-$site supervisors claim that the estimator does not adequately distinguish between routine work, such as removal of asbestos insulation around heating pipes in older homes, and non$-$routine work, such as removing asbestos$-$contaminated ceiling plaster in industrial buildings. The on$-$site supervisors believe that non$-$routine work is far more expensive than routine work and should bear higher customer charges. The estimator sums up his position in this way: $$My job is to measure the area to be cleared of asbestos. As directed by top management, I simply multiply the square metres by $$4,100$ per thousand square metres to determine the bid price. Since our average cost is only $$3,100$ per thousand square metres, that leaves enough cushion to take care of the additional costs of non$-$routine work that shows up$.$ Besides, it is difficult to know what is routine or not routine until you actually start tearing things apart.$$

To shed light on this controversy, the company initiated an ABC study of all of its costs. Data from the ABC system follow: