Herren Corporation manufactures CB radios. Each radio is sold with a two-year unconditional warranty against defects. During 2008, 280 radios were sold for $150 each. The company estimates that the warranty cost will average $20 per unit. The actual warranty costs incurred in 2008 amounted to $2,350. Prepare journal entries for the sale of CBs, the estimated warranty cost, and the actual warranty cost incurred.