at the beginning of october, the jones company had two jobs in the work in process inventory account. job a had costs of $700 already on its job cost sheet. during october, jobs incurred additional costs of $300 and was completed. job b had $500 on its job cost sheet at the start of october, and during the month another $800 was added. job b was still not finished at the end of october. what was the jones companies work in process inventory account balance on october 31? $1,000 $1,300 $0 $800