At the end of $2017,$ Waterway Company has accounts receivable of $$434,200$ and an allowance for doubtful accounts of $$24,100.$ On January $16,2018,$ Waterway Company determined that its receivable from Maximillan Company of $$4,000$ will not be collected, and management authorized its write$-$off

I dont understand the calculation of the net realizable value after waterway companys AR write off of the maximillian receivable