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: [156.41, 19.521, 110.08, -59.009, 49.787, 243.748, -25.285, -71.104, 131.859, -70.207]
Example Output: 48.58

Example Input: [169.131, -79.809, 119.898, 174.146, -1.167, 89.734, 155.318, -26.905, 182.476, 164.085]
Example Output: 94.691

Example Input: [117.712, -36.612, -78.147, 243.298, 242.312, 126.511, 88.536, -90.895, 181.052, 117.98]
Example Output:
91.175