Answer:
The journal entries are as follows:
(a)
Finished Goods Inventory A/c Dr. $111,670
To Work in process($62,890 + $48,780) $111,670
(To record completion of Job 310 and 312)
(b) Accounts receivable A/c Dr. $88,360
To Sales revenue $88,360
(To record sale of Job 312)
(c) Cost of goods sold A/c Dr. $48,780
To Finished goods inventory $48,780
(To record cost of goods sold for job 312)