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: [187.859, 5.186, 143.174, 14.744, 234.39, 236.253, 168.56, -28.843, 231.697, 148.735]

134.176