Cost classifications For each of the following costs, check the columns that most likely apply (both variable and fixed might apply for some costs). P ro d u c t C o s t s D i re c t I n d i re c t P e r i o d Va r i a b l e F i x e d Raw materials Staples used to secure packed boxes of product Plant janitors wages Order processing clerks wages Advertising expenses Production workers wages Production supervisors salaries Salesforce commissions Maintenance supplies used Presidents salary Electricity cost for of ce building Real estate taxes for Factory Of ce building