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: [-22.313, 34.813, 173.026, 195.921, -40.186, 102.217, 106.297]

78.539