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: [15.748, -13.369, -79.943, -2.78, 169.174, 101.44, -84.923, 189.589, 83.541, -37.629]
Example Output: 34.085

Example Input: [77.498, 234.955, 184.005, -48.344, 113.167]
Example Output: 112.256

Example Input: [195.111, 138.234, 84.813, 181.552, -34.974, -67.378, -0.833, 1.359, -37.444, 114.215]
Example Output:
57.466