You are asked to chart the temperature during an 8 hour period to give the average. These are your results:
7am : -10 degrees
8am: 0 degrees
9 am: 30 degrees
10 am: 36 degrees
11 am: 40 degrees
12 pm: 42 degrees
1pm: 42 degrees
2 pm: 41 degrees
What is the average temperature?