Only question 6 & 7 please Calculate the equivalent annual costs of (a) overhauling and operating the Maracas for 12 more years (with and without the new engine and control system) and (b) buying and operating the proposed replacement vessel for 20 years. You should use the real discount rate for this analysis. Based on your answer, what should RNI do? Write one to two paragraphs giving your answer and clearly explaining your reasoning and computations; show detailed computations in your Excel spreadsheet labeled Exhibit 3. 7. Why is the equivalent annual cost method potentially useful in decision making in this case? Why would you use the real discount rate to compute the EAC? What problem(s) do you see with using the equivalent annual cost method to evaluate RNIs options? One to two paragraphs.