ABSTRACT
This chapter introduces the presentation of statistical data. Data are obtained largely by two methods: When data are obtained by counting and only whole numbers are possible, the data are called discrete. The new set of values obtained by forming a frequency distribution is called grouped data. Another method of presenting grouped data diagrammatically is by using a frequency polygon, which is the graph produced by plotting frequency against class mid-point values and joining the co-ordinates with straight lines. The easiest way to draw a histogram is to mark the class mid-point values on the horizontal scale and draw the rectangles symmetrically about the appropriate class mid-point values and touching one another. The easiest way to draw a histogram is to mark class mid-point values on the horizontal scale and to draw the rectangles symmetrically about the appropriate class mid-point values and touching one another.
