1) The document discusses various graphical methods for presenting qualitative and quantitative data, including bar diagrams, pie charts, and histograms.
2) Bar diagrams and pie charts can be used to depict qualitative data by scaling the vertical axis by frequency or relative frequency of each class.
3) Histograms are used for quantitative data by drawing rectangles above each class interval, with the area corresponding to the frequency or density of observations in that interval.
4) Examples of each type of graph are provided using real data on expenditures, calorie intake, and other variables to illustrate how the graphs can be made.