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: [195.859, 108.931, 218.678, 222.393, -99.691, 9.957, -26.693, 213.845, 106.89]

105.574