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: [39.001, -7.93, -24.846, 12.843, -99.669, 155.753, -31.938, -4.944, 40.092, -19.188]

5.917