Statistics for Business: Decision Making and Analysis, 3rd Edition

Chapter Summary

A sample is a representative subset of a larger population. Samples provide sample statistics that allow us to estimate population parameters. To avoid bias, randomization is used to select items for the sample from the sampling frame, a list of items in the target population. A simple random sample (SRS) is chosen in such a way that all possible samples of size n are equally likely. Other types of samples, such as cluster samples or stratified samples, use special designs to reduce costs without introducing bias. Sampling variation occurs because of the differences among randomly selected subsets. A census attempts to enumerate every item in the population rather than a subset. Voluntary response samples and convenience samples ...