Adverteerders betaal soekenjins om advertensies te plaas op hulle webwerwe. Hulle betaal ʼn fooi gebaseer op die aantal potensiële klante wat op hulle advertensies kliek. Ongelukkig het ‘click fraud’ – m.a.w. iemand wat op ʼn advertensie kliek vir die uitsluitlike doel om die advertensieverdienste op te jaag – ʼn probleem geword. Veertig persent van adverteerders beweer dat hulle al die slagoffer van ‘click fraud’ was. Veronderstel ʼn eenvoudige ewekansige steekproef van 380 adverteerders word geneem om die effek van hierdie praktyk te ondersoek. / Advertisers pay search engines to place ads on their websites. They pay a fee based on the number of potential customers who click on their ads. Unfortunately, click fraud – i.e. someone clicking on an ad solely for the purpose of driving up advertising revenue – has become a problem. Forty percent of advertisers claim they have been a victim of click fraud. Suppose a simple random sample of 380 advertisers is taken to study the effect of this practice.

Die waarskynlikheid dat die steekproefproporsie binne ±0.04 van die populasie-proporsie is wat ‘click fraud’ ervaar, is / The probability that a sample proportion will be within ±0.04 of the population proportion experiencing click fraud, is