how do u solve this ? step by step no excel please

An investment project has annual cash inflows of $5,200,$6,300,$7,100, and $8,400, and a discount rate of 19 percent. What is the discounted payback period for these cash flows if the initial cost is $8,000 ? 2.57 years 0.82 years 3.64 vears 1.52 years 1.82 years