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: [45.213, 53.31, 191.443, -49.801, 170.298, 20.348, -70.266, 105.989, -34.239]

48.033