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: [152.683, 147.968, 62.877, -44.254, 4.344]
Example Output: 64.724

Example Input: [75.879, 43.123]
Example Output: 59.501

Example Input: [245.091, 201.984, 204.428, 222.046, 4.807, 21.497, -34.025, 160.097]
Example Output:
128.241

