Final answer:
Adding customer balances from the accounts receivable trial balance and matching it to the general ledger is an audit-related task concerning the accuracy assertion, ensuring the reliability of financial statements.
Step-by-step explanation:
The task of adding all customer balances in the accounts receivable trial balance and agreeing the amount to the general ledger is a detail related to an audit assertion which, in this case, is the assertion of accuracy. This process ensures that the balances listed in the accounts receivable trial balance, which include amounts owed by customers, accurately match the total accounts receivable recorded in the general ledger. The essence of audit assertions is to provide assurance that financial statements are reliable and conform to the Generally Accepted Accounting Principles (GAAP). Specific assertions related to accounts receivable might include completeness, existence, rights and obligations, and valuation.