The Martinez Company uses a job order costing system at its plant in Black Bay. The plant has a machining department and a finishing department. The company uses two cost driver rates for allocating manufacturing overhead costs to job orders: one on the basis of machine hours for allocating machining department overhead costs and the other on the basis of direct labor cost for allocating the finishing department overhead costs. Estimates for the current year follows: Requirements (a) Determine the two departmental cost driver rates. (b) Last month, cost records for job 111 show the following: Determine the total costs charged to job 111. (c) Explain why Martinez Company uses two different cost driver rates in its job costing system