Final answer:
To determine an account's balance, all transactions tied to the service agreements are summarized, which is akin to how one would calculate a current account balance by summing up exports, imports, and the balance column.
Step-by-step explanation:
In order to determine an account's balance, the system summarizes all transactions linked to the account's service agreements. This process is similar to calculating the current account balance in international trade, where you sum up the columns for Exports, Imports, and Balance. The final figure that you obtain is the account's current balance. This involves recording all the inflows (credits) and outflows (debits) within a specified period to ascertain the overall financial position of the account.