St. Johns River Shipyards welding machine is 15 years old, fully depreciated, and has no salvage value. However, even though it is old, it is still functional as originally designed and can be used for quite a while longer. A new welder will cost $182,500 and have an estimated life of 8 years with no salvage value. The new welder will be much more efficient, however, and this enhanced efficiency will increase earnings before depreciation from $27,000 to $74,000 per year. The new machine will be depreciated over its 5-year MACRS recovery period, so the applicable depreciation rates are 20.00%, 32.00%, 19.20%, 11.52%, 11.52%, and 5.76%. The applicable corporate tax rate is 40%, and the project cost of capital is 12%. Should the old welder be replaced by the new one?

NPV 11,468.48 is the book answer,

I have to use a finance calculator, not allowed excel. How do you work this problem, and why do you use that figure? I used 25000 for all revenue and got -48,151