Incremental Mean Update

Problem

Update a running mean with one new observation.

Given the mean of n samples and a new value x, return mean + (x - mean) / (n + 1), which is the mean of the n + 1 samples.

Hint

Pull the old mean toward the new value by 1 / (n + 1).

case 1

in: [2,3,6]

expected: 3

case 2

in: [0,0,10]

expected: 10

case 3

in: [5,1,1]

expected: 3

case 4

in: [-2,4,3]

expected: -1

Starter codePython

def incremental_mean(mean, n, x):
    # Your code here
    pass

4 test cases · run your code against them in the editor