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: [41.081, 166.314, -14.556, -84.648, -8.286]
Example Output: 19.981

Example Input: [228.031, -85.617, 36.164]
Example Output: 59.526

Example Input: [228.914, -94.905, 97.719, 62.309, 176.354]
Example Output:
94.078