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: [53.391, 118.782, 102.742]
Example Output: 91.638

Example Input: [229.28, 202.632, 129.717, 211.459, 203.204]
Example Output: 195.258

Example Input: [48.93, 238.524, -14.63, 101.761, -82.188, 82.759]
Example Output:
62.526