Robertson Corp. uses the revenue approach to account for warranties. During 2020, the company sold $ 750,000 worth of products, all of which carried a two-year warranty (included in the price). It was estimated that 2% of the selling price represented the warranty portion, and that 40% of this related to 2020, and 60% to 2021. Assuming that Robertson incurred costs of $ 5.500 to service the warranties in 2021, what is the net warranty revenue (revenue minus warranty costs) for 2021? $ 3,500 $ 5,500 $9,000 $9,500