The line graph illustrates the monthly expenditure for four different mobile phone contracts in a European country between January and September 2002, with figures measured in Euros.
Overall, Domo generally maintained the highest price point throughout the nine-month period, whereas Alpha saw a significant upward trend, particularly in the final three months. Conversely, Sim TX remained the most affordable option for the majority of the timeframe.
Domo began at 15 Euros in January and experienced fluctuations, peaking at 25 Euros in July before declining slightly to 23 Euros by September. Lex followed a similar, albeit lower, trajectory, starting at 12 Euros, dipping to 10 Euros in February, and eventually rising to 18 Euros by the end of the period.
Sim TX started at 9 Euros and remained relatively stable, reaching a high of 14 Euros in June before falling back to 8 Euros in September. In contrast, Alpha remained the cheapest contract for the first half of the year, hovering between 5 and 7 Euros. However, it underwent a sharp increase from 5 Euros in June to 25 Euros in September, overtaking all other providers to become the most expensive contract by the end of the period.