Sampling and Analytical Procedures

Section 3 is 30-40% of the AUD exam — the heaviest section — and sampling questions appear in nearly every exam form. The #1 AICPA trap is confusing the primary sampling risk concerns: for tests of controls it is assessing control risk TOO LOW (effectiveness), while for substantive tests it is INCORRECT ACCEPTANCE (accepting a misstated balance). Under AU-C 530, both statistical and nonstatistical sampling require the auditor to select a representative sample, and the choice between them does not affect audit quality — only whether results can be mathematically quantified. Candidates frequently miss that AU-C 520 requires analytical procedures at TWO mandatory stages: planning (required) and overall review near the end of the audit (required), while substantive analytical procedures during fieldwork are optional.