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: [-41.362, 123.84, 236.661, -43.042, 53.399, 15.001, 10.159, 38.886, 74.298, 167.559]
Example Output: 63.54

Example Input: [131.164, 99.999, 138.488, 57.264, -40.069, -82.402, -42.836]
Example Output: 37.373

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