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: [211.892, 69.725, 110.579, 178.646, 32.595, 163.527, 229.039, -42.103, 51.631, 165.973]
Example Output: 117.15

Example Input: [100.422, 199.731, 138.971, 95.515, 9.517]
Example Output: 108.831

Example Input: [177.091, -67.579, 78.248, 237.508, 161.951]
Example Output:
117.444