Jacob Welding, Inc. specializes in custom steel frames and uses job costing to account for its operations. The following information is available as of May 1 for the Work-in-Process Inventory account. Job# Direct Materials Direct Manufacturing Labor Overhead Total Costs 304 $3,000 $1,800 $2,520 $ 7,320 306 Total costs 4,000 $7,000 2,100 2,940 $3,900 $5,460 9,040 $16,360 Jacob Welding pays an hourly rate of $15 for direct labor. The manufacturing overhead costs are applied to jobs based on the direct labor hours used. During the month of May, Jacob Welding spends $5,800 to purchase materials and $4,650 for manufacturing overhead. The operations in May are summarized below. Material Requisition Job# Summary Time Card Summary (Hours) 304 $1,100 40 306 900 30 307 2,800 110 308 25 Total 750 $5,550 205 Jobs 304, 306, and 307 are completed in May but only Jobs 304 and 307 are delivered to customers. Required: 1. Calculate the predetermined overhead rate used. 2. Prepare the necessary journal entries for May (assuming any over- or underapplied manufacturing overhead is written off to Cost of Goods Sold account monthly).