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: [204.241, -12.158, 204.326, 79.389, 76.223, 38.435, 219.868, 12.41, 181.717]

111.606