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: [94.752, 177.315, 120.347, 120.834, 147.504, -20.013, 28.803, 214.702, 15.244, -20.225]

87.926