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: [11.574, 125.196, -0.087, 150.977, 142.293, 146.135, 19.524, 169.874, 163.098, -51.309]

87.728