Six (6 marks) Clarkes manufactures school shoes and incurs the following costs as part of its operations for the period ending 30 June 2021 Costs Factory Supervisor salary Purchase of leather and other materials 80,000 400,000 Depreciation of factory machinery 120,000 Wages for factory machine operators 180,000 Television Advertising "Back to school 50,000 campaigns" Wages for workers on the factory assembly 250,000 line Rent for factory premises Repair and Maintenance costs-factory 70,000 20,000 machinery Administration staff wages Commission to sales staff 100,000 55,000 (a) Calculate the prime costs. Show all workings including details of what costs have been included. (1 mark) (b) Calculate the total manufacturing overhead costs. Show all workings including details of what costs have been included. (1 mark) (c) Calculate the total product costs. Show all workings including details of what costs have been included. (2 marks) (d) Explain two (2) key reasons why it is important that entities understand their manufacturing costs. (2 marks)