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

1.  If your total earnings up to week 7 are 95.71328 dollars, and your total earnings up to week 18 are 109.7133 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 142.79 after having traveled for 4 hours and at milepost 178.79 after having traveled for 11 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 154.8483 cm at clock time 8 seconds and depth 176.8483 cm at clock time 13 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 9 your total earnings are 98.78732 dollars, then what will be your total earnings that the end of week 18?

5.  If an automobile is traveling at the rate of 54 mph, and is at milepost 465.4668 after having traveled for 9 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 12 cm/second between clock times 6 s and 15 s, and if its depth at clock time 6 seconds is 62.52826 cm, then what is its depth at clock time 15 seconds?

7.  If your total earnings up to week 10 are 84.86729 dollars, and if you earn money at a constant rate of 9 dollars per week, then at what week will your total earnings be 93.86729 dollars?

8.  If an automobile is traveling at the rate of 65 mph, and is at milepost 504.3759 after having traveled for 8 hours, then after how many hours of travel will it have reached milepost 16?