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: [182.34, 105.105, 248.658, 104.174, -98.917, -47.707, -61.048, 241.903, -34.659, 31.89]
Example Output: 67.174

Example Input: [-98.809, 139.617, 148.76, -52.034, 161.969, 117.253, 16.668, 164.37, -75.91, -31.599]
Example Output: 49.028

Example Input: [183.506, 81.045, 92.505, 157.792, 25.641]
Example Output:
108.098