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: [215.031, 132.087, 119.756, 202.15, 226.568, -96.253, 207.965, 111.749, -20.658, -35.875]

106.252