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: [-84.316, 211.229, 6.601, 237.546, 125.837, 94.941, 37.632, 236.012, 198.728]

118.246