4-4.) How many work in process accounts are maintained in a company that uses process costing? 4-5.) Assume that a company has two processing departments-mixing and firing. Prepare a journal entry to sho a transfer of work in process from the Mixing Department to the firing department. 4-6.) Assume that a company has two processing department-mixing followed by firing. Explain what costs might be added to the firing department's work in process account during a period