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: [198.323, 108.702, 38.704, -8.85, 57.749, 108.604, -20.56, 229.826, -85.953, 177.128]
Example Output: 80.367

Example Input: [164.048, 94.225, 164.003, -19.198, 47.156, 4.59, 170.668, 156.371, -13.172, -27.61]
Example Output: 74.108

Example Input: [141.807, 118.173]
Example Output:
129.99