I have already confirmed that question 12 is correct, but could you explain the workout to question 13. Thank you for the help.

Problem 22-2A Allocation of building occupancy costs to departments LO P2 The following information applies to the questions displayed below/ 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. Depreclation-Bullding Interest-Bullding mortgage Taxes-Building and land Gas (heating) expense Lighting expense Maintenance expense 22,500 33,750 10,000 3,125 3,750 6,875 Total occupancy cost $80,000 The bullding has 5,000 square feet on each floor. In prior perlods, the accounting manager merely divided the $80,000 occupancy cost by 10,000 square feet to find an average cost of $8 per square foot and then charged each department a bullding occupancy cost equal to this rate times the number of square feet that it occupled. Diane Linder manages a first-floor department that occuples 900 square feet, and Juan Chiro manages a second-floor department that occuples 1,800 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 $40 per square foot and second-floor space worth $20 per square foot (excluding costs for heating, lighting, and malntenance)