Three accounts have the following data

account A - Direct materials $600, Auditor labor costs $5,400 and Auditor hours 72
account B - Direct materials $400, Auditor labor costs $6,600 and Auditor hours 88
account C - Direct materials $200, Auditor labor costs $3,375 and Auditor hours 45

Overhead costs are applied to jobs on the basis of auditor horus, and the predetermined overhead rate is $55 per auditor hour. Account A is the only incomplete job at the end of the month. Actual overhead for the month was $12,000.

I need to determine the cost of each job, and come up withe balance of the Work in Process account at the end of the month as well as calculate the ending balance of the Manufacturing Overhead account for the month.

I did the following, however I am kind of lost -

Account A 72 x $55 = 3960
Account B 88 x $55 = 4840
Account C 45 x $55 = 2475

This equals 11,275. I believe I reduce the 12,000 by the 11,275 for the balance of work in process and then have to debit the Manufacturing Overhead account for the month.

Am I completely lost? Thanks for your help