5. This graph shows the outside temperature (in degrees Celsius) over the course of 12 hours, starting at midnight (x = 0).

Part I:
a) What is the domain? (1 point) _______
b) What does the domain mean in terms of the problem? (2 points)

Part II:
a) What is the range? (1 point) __________________________
b) What does the range mean in terms of the problem? (2 points)

Part III:
a) When is the function decreasing? (2 points) __________________________

b) What does this decreasing interval mean in terms of the problem? (2 points)