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: [127.638, 98.834, 122.644, 202.737, 231.832, 188.458, 194.475, -9.764, 39.303]

132.906