An investment project costs $ $19,800$ and has annual cash flows of $$4,500$ for six years $..$ What is the discounted payback period if the discount rate is zero percent? Discounted payback period b$.$ What is the discounted payback period if the discount rate is $6$ percent $?$ Discounted payback period $.$ What is the discounted payback period if the discount rate is $20$ percent $?$ Discounted payback period