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: [164.25, 170.676, 126.938, 102.143, -85.059, -6.895, 34.783]

72.405