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: [147.533, -75.226, 95.038, 210.463, 189.565, -0.611, 238.251, 77.388, 157.353, 136.831]

117.658