The chief executive officer (CEO) of a small business wishes to hire your consulting firm to conduct a simple random sample of its customers. She wants to determine the proportion of her customers who consider her company the primary source of their products. She requests the margin of error in the proportion be no more than 3% with 95% confidence. Earlier studies have indicated that the approximate proportion is 37%.
a. What is the minimum size of the sample that you would recommend to meet the requirements of your client if you use the earlier results?
b. What is the minimum size of the sample that you would recommend to meet the requirements of your client if you ignore the earlier results?
c. Is the approximate proportion of value needed in conducting the survey? Explain.