ABSTRACT
This chapter presents some introductory information about confidence intervals. Confidence, a measure of the probability of accepting what should be accepted, is important when any sampling activities are studied. Confidence intervals, which establish a range of values within which the true population value is very likely to reside, may be calculated for any parameter or statistic. There are many types of population parameters for which confidence intervals can be established. Those important in quality control applications include means, proportions, and standard deviations. Inferential statistical analysis is the process of sampling characteristics from larger populations, summarizing those characteristics or attributes, and drawing conclusions or making predictions from the summary or descriptive information. It is very common in quality control to sample from a population. And since statistical quality control programs are concerned with monitoring and maintaining product consistency, it is only natural that inferential statistics should be used.
