Net Present Value-Unequal Lives Bunker Hill Mining Company has two competing proposals: a processing mill and an electric shovel. Both pieces of equipment have an initial investme $492,019. The net cash flows estimated for the two proposals are as follows: Net Cash Flow Year Processing Mill Electric Shovel $156,000 139,000 139,000 111,000 84,000 70,000 61,000 61,000 $195,000 181,000 167,000 172,000 The estimated residual value of the processing mill at the end of Year 4 is $200,000. Present Value of $1 at Compound Interest Year 6% 10% 12% 15% 20% 10.943 0.9090.893 0.870 0.833 2 0.890 0.826 0.797 0.756 0.694 3 0.840 0.751 0.712 0.658 0.579