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 correspondingpopulation parameter.
