The line graph illustrates the median monthly contract cost for four different mobile cell phones in a European country between January and September 2002, measured in Euros. Overall, the monthly cost of three mobile cell phones showed an upward trend, albeit to varying degrees, while Alpha experienced a decline by the end of the period. Notably, all four kinds of mobile cell phones experienced fluctuations in costs over the period, and although Sim TX started at lower prices at the start of the period, its figure surged the most and surpassed all other mobile phones at the end of the period.
Domo led the pack during almost the whole period, despite being overtaken by Sim TX at the end of the period. The average cost of Domo began at 15 Euros in January, followed by a slight increase to around 17 Euros by March. From this point onward, its figure increased dramatically to a peak of 25 Euros, despite experiencing fluctuations between March and July. At the end of the period, Domo showed a decline in monthly costs and ended the period at approximately 23 Euros. In contrast, that of Lex cell phones declined from around 13 Euros in January to 10 Euros in February, before recovering by March. After this, its figure rose steadily to 14 Euros in May, and experienced fluctuations between 14 Euros and 16 Euros from May to August, reaching around 17 Euros by September.
Regarding the remaining types of cell phones, Alpha stood at just under 10 Euros at the start of the period, and its figure saw fluctuations with an upward trajectory to approximately 14 Euros by June. However, Alpha experienced a sharp decrease in cost to 10 Euros in July, before dropping steadily to around 8 Euros by September. Meanwhile, Sim TX started at 5 Euros and maintained this price until February, before rising steadily to roughly 8 Euros in April. After declining to 5 Euros again in June, its figure experienced a surge to around 14 Euros in August and to a high of 25 Euros in September, surpassing Domo cell phones at the end of the period.