Please explain each step in detail, especially when it comes to solving for NPV. I understand that NPV=$99,488.63 but I do not know how this was obtained.

Dog Up! Franks is looking at a new sausage system with an installed cost of $514,800. This cost will be depreciated straight-line to zero over the project's 9-year life, at the end of which the sausage system can be scrapped for $79,200. The sausage system will save the firm $158,400 per year in pretax operating costs, and the system requires an initial investment in net working capital of $36,960.

If the tax rate is 32 percent and the discount rate is 14 percent, what is the NPV of this project?