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

1.  If your total earnings up to week 8 are 55.9973 dollars, and your total earnings up to week 15 are 62.9973 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 316.98 after having traveled for 7 hours and at milepost 362.98 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 87.10909 cm at clock time 6 seconds and depth 102.1091 cm at clock time 14 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 12 dollars per week, and if at the end of week 5 your total earnings are 57.3803 dollars, then what will be your total earnings that the end of week 12?

5.  If an automobile is traveling at the rate of 67 mph, and is at milepost 641.4352 after having traveled for 10 hours, then what milepost would be after having traveled for 17 hours?

6.  If the depth of water in a uniform cylinder is changing at an average rate of 25 cm/second between clock times 8 s and 18 s, and if its depth at clock time 8 seconds is 195.0357 cm, then what is its depth at clock time 18 seconds?

7.  If your total earnings up to week 5 are 46.70342 dollars, and if you earn money at a constant rate of 10 dollars per week, then at what week will your total earnings be 56.70342 dollars?

8.  If an automobile is traveling at the rate of 61 mph, and is at milepost 233.683 after having traveled for 4 hours, then after how many hours of travel will it have reached milepost 10?

9.  If the depth of water in a uniform cylinder is changing at an average rate of 15 cm/second as it depth changes from 101.5315 cm at clock time 8 seconds to 116.5315 cm at an unknown clock time, then what is the unknown clock time?