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: [110.444, 23.089, -6.235, 112.579, 31.292, 190.857, 58.854, 148.587, 163.706, -5.219]
Example Output: 82.795

Example Input: [159.243, 17.964, 13.543, 175.402, -52.441, -34.741, 158.461]
Example Output: 62.49

Example Input: [128.916, 203.766]
Example Output:
166.341