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