The chart below shows the average cost of the monthly contract for four di erent mobiles cell phones in a European country from January to September 2002 measured in euro v.1

The line chart compares four different telecommunications, namely Alpha, Domo, Lex and Sim TX, in terms of the average money of monthly indenture in a particular European nation in the first three quarters of 2002. Looking at the graph, it is immediately obvious that there was an increase in the figures for all companies, except for Sim TX whose price remained fairly unchanged over the period shown. In addition, the monthly cost of Alpha' s firm experienced the most remarkable growth. In January, each person when they use Domo' s service had to pay for this corporation the highest charge, exactly 15 euros and three times higher than that of Alpha, followed by Lex telecom carrier with about 12 euros, compared to around 9 euros monthly fee of Sim TX company. In February, the amount that the Domo' s user must pay increased slightly by about 1 euro to around 16 euros, while the Lex' s rate decreased to almost 10 euros. However, since February the price of both firms rose strongly add 10 euros to nearly 24 euros for Domo and approximately 19 euros in September. On the other hand, the service charge of the other two telecommunications saw a mild rise. Details, the per-client of Sim TX and Alpha lost add about 2 euros in April. Whereas the price of Sim TX kept rising to approximately 14 euros, the figure for Alpha came back to the original cost in June. Nevertheless, there was a reversal in the last three months. The fee when one person uses Sim TX decreased significantly and almost equal with the initial cost. By contrast, the data for Alpha witnessed a growth like a rocket, at correctly 25 euros in September.