White Inc. is considering four investments. Investment 1 will yield a net present value (NPV) of $900; investment 2, an NPV of $1300; investment 3, an NPV of $1500; and investment 4, an NPV of $800. Each investment requires a certain cash outflow at the present times; investment 1, $500; investment 2, $700; investment 3, $400; and investment 4, $300. Currently, $1200 is available for investment. White Inc. is limited to only invest in at most two investments, and due to legal penalties cannot invest in investment 4 if they have invested in investment 2. Additionally, if they invest in investment 2 White Inc. must also invest in investment 1. Formulate the integer programming problem and solve using MS Excel Solver.