Classify the total costs of each of the following as variable, fixed, mixed, or step. Sales volume is the cost driver. (a) Salary of the department manager Step Variable Mixed Fixed (b) Memory chips in a computer assembly plant Mixed Fixed Variable Step (c) Real estate taxes Mixed Variable Fixed Step (d) Salaries of quality inspectors when each inspector can evaluate a maximum of 1,000 units per day Fixed Variable Mixed Step (e) Wages paid to production employees for the time spent working on products Variable Mixed Fixed Step (f) Electric power in a factory Fixed Variable Step Mixed (g) Raw materials used in production Fixed Mixed Step Variable (h) Automobiles rented on the basis of a fixed charge per day plus an additional charge per mile driven Variable Step Fixed Mixed (i) Sales commissions Step Mixed Variable Fixed (j) Depreciation on office equipment Fixed Step Variable Mixed