You are asked by the owner of the Starshine Motel to develop a customer satisfaction survey to determine the percentage of customers who are dissatisfied with service. In the past year, 20,000 customers were serviced. She desires a 95% level of confidence with an allowable statistical error of +/- 0.02. From past estimates, the manager believes that about 4% of customers have expressed dissatisfaction. What sample size should you use for this survey?