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: [219.266, 160.044, 164.151, 223.672, 97.381, -58.894, 109.643, -55.134, -54.016, 106.439]

91.255