Statistical data often include such a high number of measurements that to get an overview and to draw conclusions it is necessary to have specific mathematical tools. Some of these tools are explored in this chapter.
Data can be presented in many different ways. Some commonly used examples include dot plots, histograms, frequency tables and box plots.
In a dot plot every measurement is represented by a dot. In a frequency table, the data is grouped into several intervals that all have the same width. In a frequency table, instead of presenting each measurement separately, all the measurements in the group or interval are presented together. A histogram is a graphical representation of a frequency table. A box plot is graphical method to display statistical data that allows for immediate identification of the mean, the minimum value, the maximum value, and also intervals in with each quarter of the data values fall.
There are many methods to study and analyze statistical data. In this chapter methods, such as calculating the mean, median, and mode are introduced. Which method that is best to use in a specific case depends on what statistical data that needs to be analyzed. Therefore, the methods are also compared and advantages and disadvantages with the different methods are explained.