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: [36.936, -84.239, 129.714, -72.915, 191.701, -61.033, 2.407, -5.58, 157.689]

32.742