Classify each of the following costs as Product (direct/indirect) or Period and Variable, Fixed or Mixed (when both variable and fixed costs may apply). Costs Product (Direct/indirect) or Period Variable/Fixed/Mi Raw materials Tape used to secure packed boxes of product Plant janitors' wages Inventory clerks' wages Promotional expenses Production workers' wages Production supervisors' salaries Sales force commissions Maintenance supplies used Controller's salary Electricity cost for office building Real estate taxes for factory Real estate taxes for Office building