Oahu Inc. is considering an investment in new equipment that will be used to manufacture a smartphone. The phone is expected to generate additional annual sales of $5,100$ units at $$276$ per unit. The equipment has a cost of $$521,700,$ residual value of $$39,300,$ and an $8-$year life. The equipment can only be used to manufacture the phone. The cost to manufacture the phone follows:

Line Item Description Amount

Cost per unit:

Direct labor $$47\mathrm{.}00$

Direct materials $182\mathrm{.}00$

Factory overhead $($including depreciation$)31\mathrm{.}60$

Total cost per unit $$260\mathrm{.}60$

Determine the average rate of return on the equipment. If required, round to the nearest whole percent.