ABSTRACT
Often we are interested in creating a graphical display of a given variable or set of variables. One advantage to graphically displaying data is that large amounts of information can be presented in pictorial form, and thus can be used to present a visual summary of the underlying characteristics of the variable of interest. There are many different types of graphs and charts that can be used to display data. In this chapter, we will be discussing six basic types of graphs:
Histograms Stem-and-leaf plots Bar charts Box plots Scatter plots Marginal plots
This chapter describes these different types of graphs and provides some examples of how these graphs can be used in practice. In this chapter we will also describe how to use MINITAB to generate these different types of graphs.
The first type of graph that we will be considering is called a histogram. A histogram shows the distribution of a single continuous variable, in which the x-axis consists of the data grouped into equal-sized intervals or bins that do not overlap each other, and the y-axis represents the number or frequency of the observations that fall into each of these bins. A histogram can be drawn from a frequency distribution, which is a table that illustrates the number or frequency of the observations within the data set that fall within a given range of values. The purpose of drawing a histogram is to see the pattern of how the data are distributed over a given range of values.
