Definition: 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.
Input: [-51.642, 238.013, -43.856, 22.507, -42.668, 58.618, 182.244, 35.27, -73.154, -50.349]

27.498