The following data were extracted from the costing records of Fiddle Heart Manufacturing for September 2022. RM Salaries and wages 250,000 Petrol and oil 11,308 Insurance 21,400 General expenses 93,460 Raw material purchases 79,020 Returns of defective raw materials 4,020 Rental cost of special machine 5,000 Additional information: i. Salaries and wages consist of: 60% - production workers RM60,000 - production supervisors RM9,520 - Office administration ii. Petrol and oil must be divided between production and administration departments in the ratio of 6:4. iii. Insurance includes RM10,500 for the sales office. iv. General expenses - 35% for production, 65% for non-production departments. Required: a) Compute prime cost and production overhead. (4 marks) b)