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: [-34.349, 130.564, 245.962, -83.044, -36.899, 235.343, -56.512, 184.131, -56.903]

58.699