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: [49.831, 245.863, 226.607, 9.173, 181.411, 120.497, 159.845]

141.89