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: [171.698, -5.668, 118.313, -64.423, 141.098, 152.672, 139.97, 145.452, 2.611, 53.006]

85.473