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: [131.89, -66.422, 223.844, 140.762, -80.535, 139.088, 185.524, 152.854]

103.376