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.

[-2.869, -88.698, 21.318]
-23.416

[65.591, -56.104, -28.389, -22.521]
-10.356

[152.73, 171.885, 142.634, -92.17, -58.485, 52.649, 111.371, -96.105, -84.707, -78.322]

22.148

