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: [205.064, -88.28, 150.536, 239.481, 194.547, 129.264, 39.825, 208.173, -20.063, -60.007]

99.854