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: [83.919, -60.731, 211.379, 101.179, 97.47, -12.119, 193.099]

87.742