<image> The figure shows the distance travelled by a traveler from a city to the suburbs starting at 8:00 AM and how it changes over time. Answer the following questions based on the figure:

(1) What two variables does the graph represent? Which is the independent variable? Which is the dependent variable?
(2) What are the distances traveled at 9:00 AM, 10:30 AM, and 12:00 PM respectively?
(3) How long did he rest?
(4) What was his average speed from the time he started again after resting until he arrived at his destination?