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: [152.996, 172.675, -3.984, 177.508, 216.001, 233.337, -12.262, -8.807, -27.538]

99.992