4. 9.4 Newport Corporation purchased equipment for making pneumatic vibration isolators at a cost of $90,000 two years ago. It has a market value that can be described by the relation $90,000 − 8000 k, where k is the years from time of purchase. Experience with this type of equipment has shown that the operating cost for the first 4 years is $65,000 per year, after which it increases by $6300 per year. The asset’s salvage value was originally estimated to be $7000 after a predicted 10-year useful life. Determine the values of P, S, and AOC if a replacement study is done

(a) now and

(b) 1 year from now. Assume the expected retention period is only 1 additional year beyond the time the replacement study is performed.