Probability-to-proportional size sampling is most appropriate for measuring the total misstatement posted to an accounts payable ledger because it focuses on the size of the items being tested. This method is particularly useful when larger misstatements are of greater concern, which aligns with the need to measure total misstatements in financial accounts. Classical variable sampling (suggested answer) is generally used for estimating the monetary value of a population, but probability-to-proportional size sampling is more aligned with detecting significant misstatements.