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: [21.636, 69.324, 167.553, -32.203, 227.895, 114.505, 178.659, 189.341]

117.089