Final answer:
The most appropriate graph to show the results of testing how long different brands of gum keep their flavor is a line graph.
Step-by-step explanation:
The most appropriate graph to show your results of testing how long different brands of gum keep their flavor would be a line graph. A line graph is commonly used in science to show how one quantity changes in response to another. In this case, you can plot the time on the x-axis and the flavor fading on the y-axis. Each brand of gum can be represented by a different line on the graph, allowing you to compare and analyze the data easily.