Basic Marketing Research 7th Edition by Gilbert Churchill,Tom Brown,Tracy Suter

تمرين 8

A large manufacturer of chemicals recently came under severe criticism from various environmentalists for its disposal of industrial effluent and waste. In response, management launched a campaign to counter the bad publicity it was receiving. A study of the effectiveness of the campaign indicated that about 20% of the residents of the city were aware of the campaign and the company's position. In conducting the study, a sample of 400 was used and a 95% confidence level was specified. Three months later, it was believed that 30% of the residents were aware of the campaign. However, management decided to do another survey and specified a 99% confidence level and a margin error of +/-2 percentage points. What sample size would you recommend for this study Show all your calculations.