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: [-59.132, 236.662, -92.207, 21.809, 29.359, 129.002, 243.128, 243.356, -63.823]

76.462