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: [-23.262, 57.989, 26.8, 99.328, 109.967, -55.544, -30.089, 151.257, 58.043]

43.832