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

1.  If your total earnings up to week 8 are 104.6265 dollars, and your total earnings up to week 15 are 118.6265 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 510.4263 after having traveled for 10 hours and at milepost 562.4263 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 176.3919 cm at clock time 10 seconds and depth 195.3919 cm at clock time 15 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 7 dollars per week, and if at the end of week 9 your total earnings are 57.46883 dollars, then what will be your total earnings that the end of week 19?

5.  If an automobile is traveling at the rate of 70 mph, and is at milepost 684.2719 after having traveled for 10 hours, then what milepost would be after having traveled for 15 hours?

6.  If the depth of water in a uniform cylinder is changing at an average rate of 15 cm/second between clock times 8 s and 14 s, and if its depth at clock time 8 seconds is 104.3864 cm, then what is its depth at clock time 14 seconds?

7.  If your total earnings up to week 4 are 26.65315 dollars, and if you earn money at a constant rate of 7 dollars per week, then at what week will your total earnings be 33.65315 dollars?

8.  If an automobile is traveling at the rate of 63 mph, and is at milepost 625.1494 after having traveled for 10 hours, then after how many hours of travel will it have reached milepost 16?