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: [147.11, 6.136, 38.349, -12.25, 133.293, 108.999, 199.834, 66.233, -76.197, 234.451]

84.596