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.

Example Input: [72.755, 233.932, 245.785, 92.401]
Example Output: 161.218

Example Input: [49.462, -87.869, 36.985, 94.248, 175.789]
Example Output: 53.723

Example Input: [180.829, 49.001, 147.634]
Example Output:
125.821