Glass Grow ("GG") is a small firm that manufacture a variety of glass and windows in its Singapore plant. It has three operating departments: 1, J and K. In Department I, clear glass sheets are produced and some are sold. Department I makes coloured glass sheets, and various glass sheets (both clear and coloured) are made into windows in Department K. Department I is very labour intensive, whereas the production processes in Departments J and K are more machine intensive as the processes making of coloured glass and windows are more complex and complicated. In addition, skilled labour is required in Departments J and K to operate the machines. GG uses a plant-wide overhead allocation method using direct labour hours. The labour and machine hours expected in each department for the coming year are given below: Labour hours Machine hours Department I Department J Department K Total 72,000 36,000 28.800 136.800 1,200 7.200 10.800 19.200 GG also has three support departments: 1, 2 and 3. Department 1 handles maintenance, Department 2 manages HR and Department 3 provides marketing. Other than supporting operating departments, Department 1 provides services to Departments 2 and 3. Likewise, Department 2 provides services to all operating departments and also Departments 1 and 3. In contrast, Department 3 only supports operating departments.HR uses headcount to allocate its costs. Maintenance uses square feet (Sqft) and marketing allocates its costs equally to only the three operating departments. The following table shows the annual support department budgets, annual direct overhead costs incurred in operating departments, head count and floor area occupied for each department Department Annual department budget Annual direct overhead costs incurred in operating departments Headcount Floor area (Sqft) $167,200 2,000 15 $46,800 800 5 (Maintenance) 2 (HR) 3 (Marketing) I J K $826,000 10 1,000 $100,000 $250,000 $450,000 20 10 10 alale 10,000 10,000 20,000 (c) Compute the plant-wide allocation rate and departmental rates for GG (after allocation of support department costs). Discuss if adopting departmental rates for GG will lead to more accurate product cost. (8 marks)