Definition: 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.
Input: [218.0, -99.581, -53.244, -9.299, -32.178, 134.878, -45.933, 174.826]

35.934