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: [126.721, -59.967, 241.616, 119.302, 65.776, 176.569, 165.693, 153.632, -69.814, 76.733]

99.626