Hazman company plans to replace an old piece of equipment that is obsolete and expected to be unreliable under the stress of daily operations. The equipment is fully depreciated and no salvage value can be realized upon its disposal . Once piece of equipment being considered as replacement will provide an annual cash savings of $7,000 before income taxes and without regard to the effect of depreciation. The equipment cost $18,000 and has an estimated useful life of 5 years. No salvage value will be used for depreciation purposes because the equipment is expected to have no value at the end of 5 years. Should firm accept this investment? Please make required Calculations about NPV, IRR and Payback Period Approaches