National Bank has several departments that occupy both floors of a two-story building. The departmental accounting system has a single account, Building Occupancy Cost, in its ledger. The types and amounts of occupancy costs recorded in this account for the current period follow. DepreciationBuilding $ 31,500 InterestBuilding mortgage 47,250 TaxesBuilding and land 14,000 Gas (heating) expense 4,375 Lighting expense 5,250 Maintenance expense 9,625 Total occupancy cost $ 112,000 The building has 7,000 square feet on each floor. In prior periods, the accounting manager merely divided the $112,000 occupancy cost by 14,000 square feet to find an average cost of $8 per square foot and then charged each department a building occupancy cost equal to this rate times the number of square feet that it occupied. Diane Linder manages a first-floor department that occupies 900 square feet, and Juan Chiro manages a second-floor department that occupies 1,900 square feet of floor space. In discussing the departmental reports, the second-floor manager questions whether using the same rate per square foot for all departments makes sense because the first-floor space is more valuable. This manager also references a recent real estate study of average local rental costs for similar space that shows first-floor space worth $30 per square foot and second-floor space worth $10 per square foot (excluding costs for heating, lighting, and maintenance).