How would I start this problem? David Greene's Muffler Shop uses a normal costing system. Overhead and labor hours were estimated at $42,000 and 6,000 hours respectively, for 2010. During July 2010, only forty jobs were finished. Materials used on these jobs totaled $3,700 and labor costs were $2,700 (at $20 per hour). During 2010, 5,000 labor hours were worked and $38,000 in overhead costs were incurred. What is the total cost of the jobs finished during July