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

Exercise 12

The local gas and electric company in a city in the northeast United States recently started a campaign to encourage people to reduce unnecessary use of gas and electricity. To assess the effectiveness of the campaign, management wanted to do a survey to deter-mine the proportion of people that had adopted the recommended energy-saving measures. What sample size would you recommend if the error was not to exceed +/-0.025 percentage point and the confidence level was to be 90% Show your calculations.