An investment project provides cash inflows of $630 per year for eight years. a. What is the project payback period if the initial cost is $1,575? (Enter 0 if the project never pays back. Round your answer to 2 decimal places, e.g., 32.16.) b. What is the project payback period if the initial cost is $3,175 ? (Enter 0 if the project never pays back. Round your answer to 2 decimal places, e.g., 32.16.) c. What is the project payback period if the initial cost is $5,300 ? (Enter 0 if the project never pays back. Round your answer to 2 decimal places, e.g., 32.16.)