Inspection Paradox Mean Interval

Problem

For a renewal process with exponential interarrival times of rate lam, the interval containing a randomly chosen time is length-biased. Its mean is:

E[interval] = E[X^2] / E[X] = 2 / lam.

Return 0.0 for lam <= 0.

Hint

The exponential has E[X^2] = 2 / lam^2 and E[X] = 1 / lam.

case 1

in: [1]

expected: 2

case 2

in: [0.5]

expected: 4

case 3

in: [2]

expected: 1

case 4

in: [0]

expected: 0

Starter codePython

def inspection_paradox_mean_interval(lam):
    # Your code here
    pass

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