On July $1,2023,$ Beef Co$.($a calendar year end business$)$ purchased equipment for $$45,000$ and placed it into service. The equipment has an estimated salvage value of $$2,000$ and a useful life of $4$ years. What is the net book value of the equipment after Beef Co$.$ records depreciation on December $31,2023,$ assuming the business uses the double$-$declining balance method to compute depreciation?