Summing Things up: Graphs, Averages, Standard Deviations, Correlations and so on

Abstract

The starting point for a statistical analysis is typically data on a number of ‘variables’ (for example sex, weight, age) relating to a sample of ‘cases’ (for example people). This chapter looks at how we can summarise the pattern of a single variable, and the relationship between pairs of variables, by means of a few well-chosen numbers or graphs, and how these summaries can be interpreted.