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: [145.229, 156.739, -41.538, 174.174, 110.461, 203.548, 204.579, -25.663, -92.365]

92.796