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: [162.861, 186.665, -33.021, 135.027, 213.376, -37.163, -10.456, -77.387]

67.488