Final answer:
The most suitable graphs for displaying categorical data are bar graphs and pie charts, as bar graphs are used to compare categories or show changes over time, while pie charts are ideal for displaying parts of a whole.
Step-by-step explanation:
The most appropriate types of graphs for displaying categorical data are bar graphs and pie charts or circle graphs. In a bar graph, the length of each bar represents the number or percent of individuals in each category. Bars in a bar graph can be vertical or horizontal and are used to compare categories or show changes over time. Pie charts show categories of data as wedges in a circle, with each wedge representing a percentage of the whole, making it ideal for showing parts of a whole.
A stem-and-leaf plot, on the other hand, is useful for showing all data values within a class and mainly represents quantitative data rather than categorical data. Histograms, while similar to bar graphs, are used for displaying the distribution of quantitative, not categorical, data. Therefore, for categorical data, bar graphs and pie charts are most suitable.