Poisson CDF Prefix

Problem

The Poisson CDF at k is sum_{j=0}^{k} exp(-lambda) lambda^j / j!.

Given lambda and k, return the probability of at most k events.

Hint

Accumulate the Poisson pmf.

case 1

in: [2,1]

expected: 0.4060058497098381

case 2

in: [1,3]

expected: 0.9810118431238463

case 3

in: [0.5,0]

expected: 0.6065306597126334

Starter codePython

def poisson_cdf_prefix(lam, k):
    # Your code here
    pass

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