chapter  62
Significance testing
Pages 17

Industrial applications of statistics is often concerned with making decisions about populations and population parameters. For example, decisions about which is the better of two processes or decisions about whether to discontinue production on a particular machine because it is producing an economically unacceptable number of defective components are often based on deciding the mean or standard deviation of a population, calculated using sample data drawn from the population. In reaching these decisions, certain assumptions are made, which may or may not be true. The assumptions made are called statistical hypotheses or just hypotheses and are usually concerned with statements about probability distributions of populations.