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: [203.45, 193.726, 199.582, 32.046, 74.008, 170.209, 121.427, -33.882, 78.136, -8.04]

103.066