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.
[76.701, 59.927, 193.513, 175.441, 237.714, 72.711, 228.315, -57.487]