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.
[185.805, 8.01, 151.056, 35.572, 51.884, 217.1, -0.547, 8.171]