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: [50.54, 218.346, 19.804, 128.958, -69.364, 240.517, -80.18, 190.133, -25.446, 13.707]

68.702