You are evaluating a project for economic efficiency and have an 8% cost of capital. The project's cash flow is shown below: Is this project economically efficient? A colleague comes to you and says that by adding an input in year 5 , at a cost of $300, you can obtain an additional $500 of cash flow in year 20 of the project. Is the new project economically efficient? You are evaluating a project for economic efficiency and have an 8% cost of capital. The project's cash flow is shown below: Is this project economically efficient? A colleague comes to you and says that by adding an input in year 5 , at a cost of $300, you can obtain an additional $500 of cash flow in year 20 of the project. Is the new project economically efficient