Final answer:
The Integrated test facility is the computer assisted auditing technique that allows fictitious and real transactions to be processed together without client personnel being aware of the testing process.
Step-by-step explanation:
The computer assisted auditing technique that allows fictitious and real transactions to be processed together without client personnel being aware of the testing process is the Integrated test facility. This technique involves creating a separate test environment that mimics the client's production system.
The test transactions are then processed within this test environment along with the real transactions, allowing auditors to test the system without alerting the client personnel.