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: [115.756, 98.561, 208.286, -6.307, 213.174, 117.811, 84.705, 29.085, 59.322]

102.266