Providence Hospital generates monthly performance reports for each of its departments. The hospital must maintain an adequate staff of attending and on-call physicians at all times, so physician costs are not affected by the number of patient visits. But all other costs do vary with patient activity. Nurse-hours are used as the activity measure for nursing costs, and patient visits are used as the activity measure for the cost of supplies and other variable costs.

The head physician of the hospital's emergency room, Yolanda Mortensen, is responsible for control of costs. During October, the emergency room unit expected to treat 3,900 patients but actually treated 4,000 patients. The following additional information for October is available: