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: [60.02, -66.628, -95.571, 114.26, 109.577, 141.08, 154.303, 228.454, 46.856, 7.365]
Example Output: 69.972

Example Input: [85.354, -22.629, 51.171, 238.376, 177.126, -90.135, -84.086, 175.426, -80.74]
Example Output: 49.985

Example Input: [225.712, -27.523, -0.085, -51.494, 35.812]
Example Output:
36.484

