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.
[46.333, -23.031, 146.127, 147.589, 176.837, 11.822, 72.171]