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.
[158.725, 80.569, 50.952, -28.303, 65.35, 28.745, 30.631, 30.732]