After the invention of the steam engine in the late 1700s by the Scottish engineer James Watt, the production of machine-made goods became widespread during the 1800s. However, it was not until the 1920s that much attention was paid to the quality control of the goods being produced. In 1924, Walter Shewhart of Bell Telephone Laboratories used a statistical chart for controlling product variables; in the 1940s, quality control was used in much of wartime production.

Quality control is one of the modern uses of statistics, the branch of mathematics in which data are collected, analyzed, and interpreted. Today it is nearly impossible to read a newspaper or watch television news without seeing some type of study, in areas such as medicine or politics, that involves statistics. Other fields in which statistical methods are used include biology, physics, psychology, sociology, economics, business, education, and electronics.

The first significant use of statistics was made in the 1660s by John Graunt and in the 1690s by Edmund Halley (Halley’s Comet), when each published some conclusions about the population in England based on mortality tables. There was little development of statistics until the 1800s, when statistical measures became more widely used. Examples are the scientist Francis Galton, who used statistics in the study of human heredity, and the nurse Florence Nightingale, who used statistical graphs to show that more soldiers died in the Crimean War (in the 1850s) from unsanitary conditions than from combat wounds.

This chapter is an introduction to some of the basic concepts and uses of statistics. We first consider certain basic statistical measures. Then a section is devoted to normal distributions, followed by a section on control charts that are used in statistical process control in industry. The final sections show how to start with a set of points on a graph and find an equation that best “fits” the data. This equation, which shows a basic relationship between the variables, can be useful in research.