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: [25.333, -1.498, -55.447, 126.658, -59.362, 49.057, -31.655]

7.584