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 $1,775? (enter 0 if the project never pays back. do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) b. what is the project payback period if the initial cost is $3,450? (enter 0 if the project never pays back. do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) c. what is the project payback period if the initial cost is $5,200? (enter 0 if the project never pays back. do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.)