10. Consider a project with the following cash flows: year 1,-$400; year 2, $200; year 3, $600; year 4, $900; year 5, $1000; year 6, $250; year 7, $230. Assume a discount rate of 15% per year. a. Compute the project's NPV if cash flows occur at the ends of the respective years. b. Compute the project's NPV if cash flows occur at the beginnings of the respective years. c. Compute the project's NPV if cash flows occur at the middles of the respective years. Compute using excel. Please show functions used