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: [231.736, 52.094, -26.175, -9.307, 130.372, -25.494, -72.662, 4.873, -1.681, 139.412]

42.317