during december, maxum company sold 3,900 units of a product that carries a 60-day warranty. december sales for this product total $130,000. the company expects 10% of the units to need warranty repairs, and it estimates the average repair cost per unit will be $18.' Prepare any necessary adjusting entries at December 31, 2013, for Maxum Company’s year-end financial statements for each of the above separate transactions and events.