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: [34.89, -76.551, 144.195, -30.076, 199.798, 174.753, -48.057]

56.993