chapter 7 Sampling and Sampling Distributions BOOK

Sampling and Sampling Distributions LEARNING OBJECTIVES The two main objectives for Chapter 7 are to give you an appreciation for the proper application of sampling techniques and an understanding of the sampling distributions of two statistics, thereby enabling you to: 1. Contrast sampling to census and differentiate among different methods of sampling, which include simple, stratified, systematic, and cluster random sampling; and convenience, judgment, quota, and snowball nonrandom sampling, by assessing the advantages associated with each 2. Describe the distribution of a sample’s mean using the central limit theorem, correcting for a finite population if necessary 3. Describe the distribution of a sample’s proportion using the z formula for sample proportions What Is the Attitude of Maquiladora Workers? In 1965, Mexico initiated its widely- known maquiladora program that permits corporations from the United States and other countries to build manu- facturing facili- ties inside the Mexican border, where the company can import supplies and materials from outside of Mexico free of duty, assemble or produce products, and then export the finished items back to the country of origin. Mexico’s establishment of the maquiladora program was to promote foreign investment and jobs in the poverty-stricken country and, at the same time, pro- vide a cheaper labor pool to the participating companies, thereby reducing labor costs so that companies could more effectively compete on the world market. The maquiladora effort has been quite successful, with more than 3,500 registered companies participating and more than 1.1 million maquiladora workers employed in the pro- gram. It has been estimated that $50 billion has been spent by maquiladora companies with suppliers. Recently, industry exports were approaching $65 billion. About 1,600 of the maquiladora plants are located in the U.S.-Mexico border area, where about 40% manufacture electronic equipment, materi- als, and supplies. In recent years, the maquiladora program has spread to the interior of Mexico, where maquiladora employment growth has been nearly 30%. Maquiladora compa- nies also manufacture and assemble products from the petroleum, metal, transportation, and medical industries, among others. Whereas most maquiladora companies in the early years utilized low-skilled assembly operations, in more recent years, maquiladoras have been moving toward sophisti- cated manufacturing centers. The maquiladora program now encompasses companies from all over the world, including Japan, Korea, China, Canada, and European countries. What are the Mexican maquiladora workers like? What are their attitudes toward their jobs and their companies? Are there cultural gaps between the company and the worker that must be bridged in order to utilize the human resources more effectively? What culture-based attitudes and expectations do the maquiladora laborers bring to the work situation? How does a business researcher go about surveying workers? Managerial and Statistical Questions Suppose researchers decide to survey maquiladora workers to ascertain the workers’ attitudes toward and expectations of the work environment and the company. 1. Should the researchers take a census of all maquiladora workers or just a sample? What are reasons for each? 2. If a sample is used, what type of sampling technique would gain the most valid information? How can the researchers be certain that the sample of workers is representative of the population? 3. How can survey questions be analyzed quantitatively? Sources: Adapted from Cheryl I. Noll, “Mexican Maquiladora Workers: An Attitude Toward Working,” Southwest Journal of Business and Economics, vol. IX, no. 1 (Spring 1992), pp. 1–8; Steven B. Zisser, “Maquiladora 2001 Understanding and Preparing,” Web site located at: ide. com/; Maquila Portal (2004). Maquila Census-June 2004, retrieved July 14, 2004, ..................................................continued..........................................................