Statisticians collect and analyze mathematical data to solve problems and make predictions on future outcomes. They apply their knowledge to many different fields, including manufacturing, government, science, engineering, and public health. Using statistical techniques, statisticians can make forecasts on population growth, economic conditions, or the outcome of elections. Some statisticians work to develop the theories on which statistical techniques are based.

When statisticians are assigned a project, they first plan ways to collect the information they need. They draw on their knowledge of probability and sampling. For example, to predict the outcome of an election, statisticians might design a survey of a sample group of people who represent all the voters. Sampling substitutes the impossible task of asking every person how he or she plans to vote. Statisticians carefully develop questionnaires that yield clear answers and useful information. They supervise the workers who carry out the survey and tabulate the data. When all the information is collected, statisticians study and interpret it. They may then make recommendations to their superiors or clients.

Statisticians work on the research and marketing problems of many industries. The insurance industry employs statisticians, as do state and federal governments. The primary purpose of market research and public opinion research companies is to collect and interpret statistics. Statisticians in industry often work on quality control and product development issues. In a computer company, for instance, statisticians might design experiments that determine the failure rate of keyboards or the error rate of software. Universities employ statisticians both to teach and to do research.