Average rate of return$-$new product

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 $4,900$ units at $$257$ per unit. The equipment has a cost of $$546,800,$ residual value of $$41,200,$ and an $8-$year life. The equipment can only be used to manufacture the phone. The cost to manufacture the phone follows:

Cost per unit:

$\backslash$table$[[$Direct labor,$$41\mathrm{.}00$