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

1.  If your total earnings up to week 5 are 55.96783 dollars, and your total earnings up to week 12 are 67.96783 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 10 dollars per week, and if at the end of week 6 your total earnings are 58.82574 dollars, then what will be your total earnings that the end of week 15?

3.  If your total earnings up to week 4 are 29.26009 dollars, and if you earn money at a constant rate of 8 dollars per week, then at what week will your total earnings be 37.26009 dollars?

4.  If an automobile is at milepost 309.7968 after having traveled for 7 hours and at milepost 356.7968 after having traveled for 18 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 46 mph, and is at milepost 215.1483 after having traveled for 5 hours, then what milepost would be after having traveled for 14 hours?

6.  If an automobile is traveling at the rate of 67 mph, and is at milepost 453.2614 after having traveled for 7 hours, then after how many hours of travel will it have reached milepost 15?

7.  If the water in a uniform cylinder has depth 55.01376 cm at clock time 6 seconds and depth 65.01376 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 17 cm/second between clock times 5 s and 13 s, and if its depth at clock time 5 seconds is 74.94995 cm, then what is its depth at clock time 13 seconds?