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refers to a group of transactions having mon characteristics, such as cash receipts or cash disbursements, but which are not simply added together and presented as an account balance in financial statements.Population(總體) is the set of all items that constitute an account balance or class of transactions.A sample(樣本) is a set of sampling units.抽樣風(fēng)險(xiǎn)(sampling risk)和非抽樣風(fēng)險(xiǎn)(nonsampling risk)Sampling risk is defined as the probability that an auditor’s conclusion based on a sample might be different from the conclusion based on an audit of the entire population.控制測(cè)試中的抽樣風(fēng)險(xiǎn):信賴過(guò)度風(fēng)險(xiǎn)和信賴不足風(fēng)險(xiǎn)Sampling risk in test of controls includes overdependence risk and underdependence risk.細(xì)節(jié)測(cè)試中的抽樣風(fēng)險(xiǎn):誤受風(fēng)險(xiǎn)和誤拒風(fēng)險(xiǎn)Sampling risk in substantive test prises the risk of incorrect acceptance and the risk of incorrect rejection.信賴過(guò)度風(fēng)險(xiǎn)和誤受風(fēng)險(xiǎn)影響審計(jì)的效果,信賴不足風(fēng)險(xiǎn)和誤拒風(fēng)險(xiǎn)影響審計(jì)的效率。Overdependence risk and the risk of incorrect acceptance are related to the effectiveness of audit, while underdependence risk and the risk of incorrect rejection affects the efficiency of audit.Nonsampling risk is all risk other than sampling risk.統(tǒng)計(jì)抽樣(statistical sampling)和非統(tǒng)計(jì)抽樣(nonstatistical sampling)Statistical sampling is defined as audit sampling that uses the laws of probability for selecting and evaluating a sample from a population for the purpose of reaching a conclusion about the population. Nonstatistical sampling is audit sampling in which auditors do not utilize statistical calculations to express the results.審計(jì)抽樣的步驟:steps of audit sampling(一)樣本設(shè)計(jì):確定測(cè)試目標(biāo)—定義總體與抽樣單元(總體、抽樣單元、分層)—定義誤差構(gòu)成條件Designing the sample: specify the test objectives—define population and sampling unit(population, sampling unit, stratification)—define the deviation conditions (. “Select a sample of recorded sales invoices, vouch them to supporting shipping orders, and document cases where the shipping order is missing” is a well defined deviation condition in test of controls )(二)選取樣本:確定樣本規(guī)?!x取樣本—對(duì)樣本實(shí)施審計(jì)程序Select the sample: determine the sample size—select the sample—perform audit procedures on the sample1.影響樣本規(guī)模的因素:(1)可接受的抽樣風(fēng)險(xiǎn);(2)可容忍誤差;(3)預(yù)計(jì)總體誤差;(4)總體變異性;(5)總體規(guī)模 Five influences on sample size: (1)acceptable sampling risk(sample size varies inversely with the amount of sampling risk an auditor is willing to take)。(2)tolerable error rate (sample size varies inversely with the tolerable error rate);when being used in test of controls, tolerable error rate is tolerable deviation rate(可容忍控制偏差率)。 when used in substantive test, tolerable error rate refers to tolerable misstatement rate(可容忍錯(cuò)報(bào)率)(3)Expected population error rate (sample size varies directly with the Expected population error rate) ;Expected misstatement has the effect of reducing the allowable tolerable misstatement. The more misstatement expected, the less “tolerable misstatement cushion” remains. (4)Variability within the population (Generally, this factor is only taken into account in substantive test. Sample size should vary directly with the magnitude of the variability of population. Populations with high variability should be stratified);(5) Population size (unless the population is very small, generally population size has no effect on sample size)2.選取樣本的方法:(1)使用隨機(jī)數(shù)表或計(jì)算機(jī)輔助審計(jì)技術(shù)選樣;(2)系統(tǒng)選樣:也稱等距選樣,選樣間距=總體規(guī)模247。樣本規(guī)模;(3)隨意選樣Methods of selecting the sample: (1) using random number table or puterassisted auditing technique。 (2) systematic random selection: selection interval=population size247。sample size。 (3) haphazard selection(三)評(píng)價(jià)樣本結(jié)果:分析樣本誤差—推斷總體誤差—形成審計(jì)結(jié)論Evaluate the auditing results on the sample: analyze the sample error—project the population error—form audit conclusion練習(xí)題:1.請(qǐng)看2008年審計(jì)輔導(dǎo)教材P272273Suppose an auditor determines that the acceptable overdependence risk is 10%, the tolerable deviation rate is 7%, and the expected population deviation rate is %.According to the statistical sampling size table, what is the sample size should be?2. 請(qǐng)看2008年審計(jì)輔導(dǎo)教材P275Suppose an auditor has performed audit procedures on 56 selected items, and no deviation has been found. If the acceptable overdependence risk is 10%, determine the maximum population deviation rate based on the following risk factor table.Maximum population deviation rate (MDR)= risk factor247。sample size= 247。56=%The result shows that there is a 10% risk that the effective population deviation rate would exceed %, . you have a 90% confidence level to ensure that the effective population deviation rate do not exceed %. Given a 7% tolerable deviation rate, it is concluded that the probability that the effective population deviation rate exceeds the tolerable deviation rate is very low, and the population can be accepted.3.請(qǐng)看2008年審計(jì)輔導(dǎo)教材P281表129樣本規(guī)模表 sample size table可接受誤受風(fēng)險(xiǎn) acceptable risk of incorrect acceptance預(yù)計(jì)錯(cuò)報(bào)占可容忍錯(cuò)報(bào)的百分比 percentage of estimated misstatement over tolerable misstatement可容忍錯(cuò)報(bào)占總體的百分比 percentage of tolerable misstatement over population4. 樣本規(guī)模=保證系數(shù)總體賬面金額/可容忍錯(cuò)報(bào)Sample size = assurance factorpopulation recorded amount/tolerable misstatementP282表1210評(píng)估的重大錯(cuò)報(bào)風(fēng)險(xiǎn) evaluated risk of significant misstatement其他實(shí)質(zhì)性程序未能發(fā)現(xiàn)重大錯(cuò)報(bào)的風(fēng)險(xiǎn) the risk that other substantive procedures fail to detect significant misstatement最高、高、中、低 highest/high/moderate/low5. 請(qǐng)看2008年審計(jì)輔導(dǎo)教材P283推斷總體錯(cuò)報(bào) project population misstatement比率法和差額法 ratio method/average difference methodNote: a negative misstatement indicates overstatement of the book value, and a positive misstatement indicates understatement.(1) Applying the difference method:For stratum 1, projected population misstatement (PPM) =600For stratum 2, PPM = 80(274)/23 = 953For stratum 3, PPM = 168(66)/22 = 504For stratum 4, PPM = 342(88)/22 = 1,368For stratum 5, PPM = 91023/23 = 910Total PPM = 6009535041368+910 = 2,515(1) Applying the ratio method:For stratum 1, projected population misstatement (PPM) =600For stratum 2, PPM = (274)247。(21700/75068) = 948For stratum 3, PPM = (66) 247。(9476/75008) = 522For stratum 4, P