Business statistics

Chapter 2. Descriptive Statistics: Tabular and Graphical Presentations

• In this chapter we start by developing numerical summary measures for data sets consisting of a single variable.
• When a data set contains more than one variable, the same numerical measures can be computed separately for each variable. However, in the two-variable case, we will also develop measures of the relationship between the variables.
• Numerical measures of location, dispersion, shape, and association are introduced. If the measures are computed for data from a sample, they are called sample statistics.
• If the measures are computed for data from a population, they are called population parameters. In statistical inference, a sample statistic is referred to as the point estimator of the corresponding population parameter.