ABSTRACT
In this chapter, the authors discuss how they describe measurements samples of the whole population. For instance, the well-known average value is a single number computed from a larger sample that summarizes one of the characteristics of the sample. The sum of squares is represented in the graphical method, where the x-axis denotes the weekly allowance from 1 to 8, with an increasing order of 1 unit. The plot line represents the mean allowance, and the dots represent the individual allowances. The readers can easily compute the area of each square as the number of little squares on the graph paper within each drawn square, and then the mean area of the squares, which is exactly the variance. The difference in weight was evident, but this is only a visual inspection of the data.
