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: [63.795, 57.14, -85.188, 205.568, 239.148, -22.972, 77.724]

76.459