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: [-11.208, 57.135, -56.473, 36.973, -10.288, -18.376, -67.063, 166.957, 8.378, 191.148]

29.718