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: [156.41, 19.521, 110.08, -59.009, 49.787, 243.748, -25.285, -71.104, 131.859, -70.207]

48.58