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: [40.841, 73.133, 153.316, 239.076, -44.567, 142.629, -11.647, 150.54, 122.516, 125.602]

99.144