In 2020, Quapau Products introduced a new line of hot water heaters that carry a one-year warranty against manufacturers defects. Based on industry experience, warranty costs were expected to approximate 5% of sales revenue. First-year sales of the heaters were $390,000. An evaluation of the companys claims experience in late 2021 indicated that actual claims were less than expected4% of sales rather than 5%. Assuming sales of the heaters in 2021 were $440,000 and warranty expenditures in 2021 totaled $15,600, what is the 2021 warranty expense?