An auditor may perform the following three types of substantive procedures: (1) tests of details of transactions; (2) tests of details of balances; and (3) analytical procedures. Below are specific audit procedures that fall within one of these categories: 1. Calculate expected payroll costs from last years amount adjusted for staff changes and pay rise in the year. 2. Attend the factory on the final day of the year to review work in progress. 3. Agree a sample of sales invoices to goods despatch records held in the inventory system. 4. Review post year-end receipts from customers to establish the extent of unpaid debts.

Required: For each procedure, classify which of the three types it belongs to.