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

1.  If your total earnings up to week 10 are 96.0267 dollars, and your total earnings up to week 15 are 106.0267 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 15 dollars per week, and if at the end of week 4 your total earnings are 59.3451 dollars, then what will be your total earnings that the end of week 15?

3.  If your total earnings up to week 8 are 82.90165 dollars, and if you earn money at a constant rate of 11 dollars per week, then at what week will your total earnings be 93.90165 dollars?

4.  If an automobile is at milepost 350.1238 after having traveled for 9 hours and at milepost 389.1238 after having traveled for 20 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 33 mph, and is at milepost 180.5952 after having traveled for 6 hours, then what milepost would be after having traveled for 15 hours?

6.  If an automobile is traveling at the rate of 73 mph, and is at milepost 424.9064 after having traveled for 6 hours, then after how many hours of travel will it have reached milepost 12?

7.  If the water in a uniform cylinder has depth 34.57789 cm at clock time 4 seconds and depth 45.57789 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 12 cm/second between clock times 10 s and 18 s, and if its depth at clock time 10 seconds is 103.151 cm, then what is its depth at clock time 18 seconds?