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

1.  If your total earnings up to week 5 are 48.60421 dollars, and your total earnings up to week 10 are 58.60421 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 278.7594 after having traveled for 8 hours and at milepost 315.7594 after having traveled for 18 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 125.4409 cm at clock time 4 seconds and depth 158.4409 cm at clock time 11 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 10 dollars per week, and if at the end of week 9 your total earnings are 82.60838 dollars, then what will be your total earnings that the end of week 15?

5.  If an automobile is traveling at the rate of 54 mph, and is at milepost 376.2532 after having traveled for 7 hours, then what milepost would be after having traveled for 18 hours?

6.  If the depth of water in a uniform cylinder is changing at an average rate of 24 cm/second between clock times 6 s and 15 s, and if its depth at clock time 6 seconds is 128.3066 cm, then what is its depth at clock time 15 seconds?

7.  If your total earnings up to week 9 are 85.59906 dollars, and if you earn money at a constant rate of 10 dollars per week, then at what week will your total earnings be 95.59906 dollars?

8.  If an automobile is traveling at the rate of 61 mph, and is at milepost 300.3414 after having traveled for 5 hours, then after how many hours of travel will it have reached milepost 15?