Global warming? Mario and Carlos don't believe it! They have been collecting data to determine the average monthly temperature at 30 sites throughput the state. The samples, recorded in Celsius, have been compiled in a spread sheet. Marge and Carlos would like to show the change in average temperatures in the state, over time span of 5 years, in a presentation to the states environment agencies. What would be the BEST way to represent this data that illustrates changes in average temperatures over time?