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: [39.516, -43.961, -54.183, 5.186, 0.495, 131.744, -97.181, 131.921, 181.318]

32.762