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: [93.34, 211.631, 173.556, -91.68, 236.096]
Example Output: 124.589

Example Input: [-41.714, 218.588, 49.769, 142.519, 179.776, -99.226, 224.69, 191.642]
Example Output: 108.256

Example Input: [-9.014, 248.261, 225.233]
Example Output:
154.827

