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: [59.225, 44.897, 97.858, -74.683, 228.261, -31.273, 62.844]

55.304