Global warming? Marge and Carlos do not believe it! They have been collecting data to determine the average monthly temperature at thirty sites throughout the state. The samples, recorded in degrees Celsius, have been compiled in a spread sheet. Marge and Carlos would like to show the change in average temperature in the state, over a time span of five years, in a presentation to the state's environmental agencies. What would be the BEST way to represent this data that illustrates change in average temperature over time?