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: [43.362, 111.151, 162.709, 43.974, 184.165, 238.15, 181.927]
Example Output: 137.92

Example Input: [-20.702, 4.455, 37.838, 102.751, 231.6, -23.075, 236.527, 227.109, 171.708, 46.239]
Example Output: 101.445

Example Input: [110.206, 77.406]
Example Output:
93.806