Acme Company plans to add a new product line. The project requires an initial investment of $$285,000$ and has an expected useful life of $9$ years. The project is expected to generate the following annual results: cash revenues of $$250,000,$ cash operating expenses of $$198,000,$ depreciation expense of $$20,000,$ and annual incremental net operating income of $$32,000.$ What is the payback period of this project in years? Round to one decimal place.

$4\mathrm{.}6$ years

$5\mathrm{.}5$ years

$6\mathrm{.}8$ years

$8\mathrm{.}9$ years

None of the above