the following transactions occurred this period for metlock corp. as it created custom-order scented bubble bath: cost of labor, $15,400; cost of scented oils used, $8,900; and applied moh, $6,300. metlock started the period with $4,000 in its wip inventory account. the total cost of jobs completed this period was $29,600. what is the ending balance of metlock’s wip inventory account this period?