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: [199.39, 166.408, 103.51, 148.207, -35.424, 124.444, -92.572, 19.52, 62.361]

77.316