Quantitative data can be summarised numerically, and the most common techniques are indicated in Table 13.9. The mean and standard deviation are usually used whenever possible, for practical and mathematical reasons. Sometimes quoting both the mean and median (and the standard deviation and IQR) may be appropriate.
The following short video may help explain some of these concepts:
|Feature:||Approximately symmetric||Not symmetric, or outliers|
|Shape:||Verbal description only||Verbal description only|
|Outliers:||Standard deviation rule||IQR rule|