4. (10 marks) A maintenance department is using a 9 year old machine that had an initial cost of S13,500 and a useful life of 13 years. Its value depreciates by $1000 per year. Its operating costs are estimated to be $2,000 for next year with an increase of $350 every year thereafter. At the present time, the department is considering replacing this machine with a new one that costs $11,500. The operating and maintenance costs for this new machine average $1050 the first year and will increase by 15% per year thereafter. The depreciation rate for this machine is 20%. It has a useful life of 10 years with an economic life of 8 years. Should the current machine be replaced now? If not, when? Use a MARR of 10%