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: [184.703, 187.544, -53.998, 226.499, 113.867, 68.459, 171.872, 226.16, 51.401]

130.723