3. You are the mayor of a small town, and an oil company is offering you $100,000 to locate a new refinery in your town. There is a report that this refinery will cost your town $15,000 in health costs each year for the next 10 years that it operates. Your discount rate is 6%. (a) Write down an equation that calculates the Net Present Value (NPV) of this choice (b) Solve for the NPV. I recommend using Excel (NPV function) or a similar program