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

1.  If your total earnings up to week 5 are 52.38483 dollars, and your total earnings up to week 15 are 63.38483 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 you are earning money at an average rate of 14 dollars per week, and if at the end of week 8 your total earnings are 110.5785 dollars, then what will be your total earnings that the end of week 18?

3.  If your total earnings up to week 7 are 89.86034 dollars, and if you earn money at a constant rate of 13 dollars per week, then at what week will your total earnings be 102.8603 dollars?

4.  If an automobile is at milepost 241.327 after having traveled for 4 hours and at milepost 303.327 after having traveled for 15 hours, then what is its average speed? Why do we say average speed rather than just speed?

5.  If an automobile is traveling at the rate of 55 mph, and is at milepost 209.1874 after having traveled for 4 hours, then what milepost would be after having traveled for 13 hours?

6.  If an automobile is traveling at the rate of 74 mph, and is at milepost 435.4923 after having traveled for 6 hours, then after how many hours of travel will it have reached milepost 14?

7.  If the water in a uniform cylinder has depth 158.3485 cm at clock time 7 seconds and depth 183.3485 cm at clock time 15 seconds, then at what average rate is the depth changing? What we say average rate rather than just rate?

8.  If the depth of water in a uniform cylinder is changing at an average rate of 27 cm/second between clock times 8 s and 19 s, and if its depth at clock time 8 seconds is 206.4813 cm, then what is its depth at clock time 19 seconds?