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.
[199.57, 59.623, -94.857, -78.117, 137.123, 247.573, 80.311, 198.771]