Hypergeometric PMF

Problem

Hypergeometric probability mass function: sampling draws items without replacement from a population with the given number of successes.

P(X = x) = C(successes, x) * C(pop - successes, draws - x) / C(pop, draws). Return 0.0 for impossible draws.

Hint

Choose x successes and draws - x failures, then divide by all possible draws.

case 1

in: [52,4,5,2]

expected: 0.03992981808107859

case 2

in: [10,3,4,2]

expected: 0.3

case 3

in: [10,3,4,0]

expected: 0.16666666666666666

case 4

in: [10,3,4,4]

expected: 0

case 5

in: [5,5,5,5]

expected: 1

Starter codePython

import math


def hypergeometric_pmf(pop, successes, draws, x):
    # Your code here
    pass

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