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

1.  If your total earnings up to week 7 are 69.4873 dollars, and your total earnings up to week 14 are 79.4873 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 321.3256 after having traveled for 6 hours and at milepost 376.3256 after having traveled for 16 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 168.6898 cm at clock time 8 seconds and depth 192.6898 cm at clock time 19 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 15 dollars per week, and if at the end of week 8 your total earnings are 116.7072 dollars, then what will be your total earnings that the end of week 13?

5.  If an automobile is traveling at the rate of 72 mph, and is at milepost 693.3652 after having traveled for 10 hours, then what milepost would be after having traveled for 19 hours?

6.  If the depth of water in a uniform cylinder is changing at an average rate of 35 cm/second between clock times 7 s and 17 s, and if its depth at clock time 7 seconds is 225.795 cm, then what is its depth at clock time 17 seconds?

7.  If your total earnings up to week 10 are 58.64475 dollars, and if you earn money at a constant rate of 6 dollars per week, then at what week will your total earnings be 64.64475 dollars?

8.  If an automobile is traveling at the rate of 67 mph, and is at milepost 602.8336 after having traveled for 9 hours, then after how many hours of travel will it have reached milepost 19?