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: [179.836, 115.658, -58.613, 29.591, 198.709]
Example Output: 93.036

Example Input: [218.807, 72.849, 7.838, 124.81, 45.929, 239.888]
Example Output: 118.354

Example Input: [-31.505, -25.291, -88.299, 23.561, 182.747, 144.445, 84.875]
Example Output:
41.505

