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: [236.753, 184.794, -45.415, 20.278, -41.34, 109.146, 176.83]
Example Output: 91.578

Example Input: [84.13, 59.186, 115.606]
Example Output: 86.307

Example Input: [-95.448, 38.025, 230.71, 84.936, 110.345, 61.64, 173.756]
Example Output:
86.281