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: [52.696, 230.416, 89.385, 227.188, -81.137, 239.638, 64.455, -84.734, -73.041]

73.874