Figure 3.13: Box and whisker plot for the variable ASCORE1, total A-level score (stem and leaf plot adjacent)

In large data sets with continuous variables a grouped frequency table may be used to obtain a general picture of data distributions. For example, look at the values of the variable AGEY (Age in years) in Figure 3.12. It is difficult to discern any pattern in the distribution of ages. Rearrangement of the data in a grouped frequency table may provide a clearer picture of the distribution of ages.