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

1.  If your total earnings up to week 10 are 55.62531 dollars, and your total earnings up to week 18 are 61.62531 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 223.0256 after having traveled for 5 hours and at milepost 270.0256 after having traveled for 13 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 51.65516 cm at clock time 4 seconds and depth 64.65516 cm at clock time 9 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 11 dollars per week, and if at the end of week 4 your total earnings are 43.7582 dollars, then what will be your total earnings that the end of week 12?

5.  If an automobile is traveling at the rate of 73 mph, and is at milepost 288.1891 after having traveled for 4 hours, then what milepost would be after having traveled for 14 hours?

6.  If the depth of water in a uniform cylinder is changing at an average rate of 27 cm/second between clock times 4 s and 13 s, and if its depth at clock time 4 seconds is 101.648 cm, then what is its depth at clock time 13 seconds?

7.  If your total earnings up to week 9 are 57.97668 dollars, and if you earn money at a constant rate of 7 dollars per week, then at what week will your total earnings be 64.97668 dollars?

8.  If an automobile is traveling at the rate of 62 mph, and is at milepost 475.9063 after having traveled for 8 hours, then after how many hours of travel will it have reached milepost 15?