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: [-1.794, 20.868, -98.98, 76.164, 5.808, -59.338, -76.515, -90.202, -77.626, 150.554]

-15.106