Covariance of Two Indicators

Problem

Covariance of two indicator random variables.

Cov(A, B) = P(A and B) - P(A) * P(B). Inputs are p_a, p_b and the joint probability p_ab.

case 1

in: [0.5,0.4,0.2]

expected: 0

case 2

in: [0.5,0.4,0.3]

expected: 0.09999999999999998

case 3

in: [0.2,0.2,0.2]

expected: 0.16

case 4

in: [0.5,0.5,0]

expected: -0.25

Starter codePython

def covariance_two_indicators(p_a, p_b, p_ab):
    # Your code here
    pass

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