In this task you will be given a list of numbers and you need to find the mean (average) of that list. The mean of a list can be found by summing every number in the list then dividing the result by the size of that list. The output should be rounded to 3 decimal places.

Example Input: [-81.517, 126.001, 203.19, 236.819, 36.037, 152.691, -1.444, -37.296]
Example Output: 79.31

Example Input: [118.319, 70.462]
Example Output: 94.39

Example Input: [33.948, 132.405, -69.128, 33.296, 35.864, -58.743, 62.847, 237.149, 54.19]
Example Output:
51.314