rted into these classes. Third, the number of items in each class must be counted. The final step in creating a frequency distribution involves displaying the results in either a chart or a table.
The print media commonly make use of frequency distributions. Newspaper and magazine articles often include both charts and tables. Just one example would be the display of election returns. Obviously this data is comprised of numerous ballots. To make the ballots more comprehensible, frequency distributions are created. This process involves counting the ballots and subdividing the votes. The frequency distribution then shows the number of votes received by each candidate.
Unfortunately, while frequency distributions present data in a relatively compact form, there are usually some types of information that can only be obtained from the original data. Therefore, although frequency distributions provide data that is more usable, they do so at a price. While certain information must be lost, this ultimately provides the data with increased comprehensibility.
Most any kind of data contains values which are not all alike. Very often, the degree to which values are unalike is of considerable significance. Therefore, statisticians frequently attempt to define data's variability, or dispersion. Perhaps the simplest and crudest measure of dispersion consists of range. The range of given set of data is simply the difference between its highest and lowest values.
Range is both easy to calculate and easy to understand. Moreover, people have a tendency to focus their attention on highest and lowest values. However, while the range of a given set of data may be interesting, it is not generally a useful measure of variability. This is primarily because range says nothing about the dispersion of values which fall between the two extremes.
Range values are typically employed as "quick and easy" indications ...