Solve the following by describing a picture, and by constructing a graph:

1.  If your total earnings up to week 4 are 31.95977 dollars, and your total earnings up to week 14 are 39.95977 dollars, then what are your average earnings per week? Why do we say average earnings per week rather than just earnings per week?

2.  If an automobile is at milepost 627.8648 after having traveled for 9 hours and at milepost 697.8648 after having traveled for 15 hours, then what is its average speed? Why do we say average speed rather than just speed?

3.  If the water in a uniform cylinder has depth 181.6429 cm at clock time 9 seconds and depth 202.6429 cm at clock time 14 seconds, then at what average rate is the depth changing? What we say average rate rather than just rate?

4.  If you are earning money at an average rate of 6 dollars per week, and if at the end of week 6 your total earnings are 32.38619 dollars, then what will be your total earnings that the end of week 12?

5.  If an automobile is traveling at the rate of 51 mph, and is at milepost 196.4429 after having traveled for 4 hours, then what milepost would be after having traveled for 9 hours?

6.  If the depth of water in a uniform cylinder is changing at an average rate of 6 cm/second between clock times 9 s and 16 s, and if its depth at clock time 9 seconds is 33.81828 cm, then what is its depth at clock time 16 seconds?

7.  If your total earnings up to week 7 are 44.94769 dollars, and if you earn money at a constant rate of 7 dollars per week, then at what week will your total earnings be 51.94769 dollars?

8.  If an automobile is traveling at the rate of 75 mph, and is at milepost 521.6156 after having traveled for 7 hours, then after how many hours of travel will it have reached milepost 16?