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.
[112.638, 131.471, -68.982, 243.149, -30.086, 28.129, 15.18, 175.322]