Population Excess Kurtosis

Problem

Return the population excess kurtosis: (1/n) * sum((x - mean)^4) / std^4 - 3. Return 0.0 if data is empty or the standard deviation is zero.

Hint

Fourth central moment over variance squared, minus 3.

case 1

in: [[1,2,3,4,5]]

expected: -1.3

case 2

in: [[1,2,3,4,10]]

expected: -0.21199999999999974

case 3

in: [[5,5,5]]

expected: 0

case 4

in: [[1,1,2,2]]

expected: -2

case 5

in: [[1,2,3]]

expected: -1.5

Starter codePython

def kurtosis(data):
    # Your code here
    pass

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