Kế toán, kiểm toán - Module G variables sampling learning objectives

Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill/IrwinModule G Variables SamplingLearning ObjectivesDefine variables sampling and understand when variables sampling is used in the audit.Understand the basic process underlying monetary unit sampling (MUS) and when to use it.Identify the factors affecting the size of an MUS sample and calculate the sample size for an MUS application.Evaluate the sample results for an MUS sample by calculating the projected misstatement, incremental allowance for sampling risk, and basic allowance for sampling risk.Understand the basic process underlying classical variables sampling and the use of classical variables sampling in an audit.Understand the use of nonstatistical sampling for variables sampling.Mod G-2Variables SamplingUsed to estimate the amount (or value) of a population Substantive proceduresTypes of variables sampling approachesMonetary unit sampling (MUS) Classical variables samplingMod G-3Monetary Unit Sampling (MUS) Defines the sampling unit as individual dollar (or Euro, Yen, Yuan, etc.) in an account balanceAuditor will select individual dollars for examinationAuditor will verify entire “logical unit” containing the selected dollarMod G-4When to use MUSADVANTAGES OF MUSDISADVANTAGES OF MUSMod G-5Major Steps in Variables Sampling: PlanningDetermine the objective of samplingDefine characteristic of interest Define the populationMod G-6Major Steps in Variables Sampling: PerformingDetermine sample sizeSelect sample itemsMeasure sample itemsMod G-7Using AICPA MUS TablesRatio of Expected to Tolerable MisstatementTolerable Misstatement as a Percentage of PopulationFind appropriate Risk of Incorrect AcceptanceFind Appropriate Ratio of Expected to Tolerable MisstatementRead across to “Tolerable Misstatement as a Percentage of Population” columnMod G-8Major Steps in Variables Sampling: EvaluatingEvaluate sample resultsUpper Limit on MisstatementsMod G-9Upper Limit on MisstatementsIf Upper Limit on Misstatements is $50,000 and risk of incorrect acceptance is 5%There is a 5% probability that the true misstatement exceeds $50,000There is a 95% probability that the true misstatement is less than or equal to $50,000 95% 5% $0 $50,000Mod G-10Projected MisstatementAssumes the entire sampling interval contains the same percentage of misstatement as the item examined by the auditorDo not calculate if balance > sampling intervalTainting % = Amount of Misstatement Recorded Balance of ItemProjected = Sampling Interval x Tainting % Misstatement Mod G-11Basic Allowance for Sampling RiskIncremental Allowance for Sampling RiskMod G-12Evaluate ResultsIf upper limit on misstatements tolerable misstatementMod G-13MUS Sampling vs. Classical Variables SamplingMUS is more appropriate when:Classical variables sampling is more appropriate when:Mod G-14Mean per Unit Sampling (Sample Size)Sample size N x [R(IR) + R(IA)] x SD 2 TE - EEDifferences from MUS samplingMod G-15Evaluating ResultsPrecision = N X R(IA) X (SD ÷ √n )Project sample average to population estimateAdd/subtract precision to get precision intervalDetermine difference between account balance and furthest bound of precision intervalIf greater than tolerable misstatement—reject balanceDetermine cause of all misstatementsMod G-16Other ApproachesStratified samplingDifference estimationRatio estimationMod G-17Nonstatistical SamplingDoes not measure the auditor’s exposure to sampling riskPermitted under generally accepted auditing standardsDifferencesDoes not consider sampling risk in determining sample size or evaluating sample resultsMay use a nonprobabilistic selection technique Mod G-18BASIC PROCEDURESelect sampleDoes not explicitly consider sampling risk in determining sample sizeMay use block or haphazard selection methodsMeasure sample items (same as statistical sampling)Mod G-19Evaluate Sample ResultsDifference estimationRatio estimationUse judgment to allow for sampling riskNormally reject if projected misstatement exceeds expected misstatementMod G-20DocumentationObjective and assertions evaluatedSampling technique used and definition of a misstatementMethod and parameters used to determine sample sizeSample sizeSelection methodDescription of audit proceduresDetermination of upper limit on misstatement, precision, or projected misstatementConclusion—effect on audit opinionMod G-21