3 examples of error which are not revealed by trial balance and the step of auditor would take to detect them?

1- when installing many nozzels have the same size and same thickness in the same pressure vessel and after installing someone wrong & the auditor of storage found missing valve before the nozzle.

2- the profit of the project is calculated by 15% from the total amount will payed and after the auditor check every thing found the missing Engineers Salary and the profit will became 12%

3- when comp. arrange to buy laptops for the employes and it will cost 10,000$ and after the auditor review found there is taxes & Fees Missied about 2,500$

1. An entry is not posted completely: the auditor can take the sequence of entries for the relevant period and trace it for completeness of posting

2.  An entry is posted to wrong debit and credit accounts: the auditor can take a sample of entries and review its posting

3. A fictitious entry was posted: the auditor may take a sample of entries and check for supporting documents