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: [-96.229, 200.453]
Example Output: 52.112

Example Input: [226.287, 114.252, -53.47, 8.606, 234.708, -31.872, 163.615]
Example Output: 94.589

Example Input: [35.47, -32.47, -93.557, 152.479, 190.059, 67.967, 93.939, 54.545, 27.758, 74.86]
Example Output:
57.105