The probability that a randomly selected 3yearold male stink

The probability that a randomly selected 3-year-old male stink bug will live to be 4 years old is 0.91804.
(a) What is the probability that two randomly selected 3-year-old male stink bugs will live to be 4 years old?
(b) What is the probability that eight randomly selected 3-year-old male stink bugs will live to be 4 years old?

Solution

p = prob will live upto 4 years =0.91804

q = prob that will not live upto 4 years = 1-0.91804 = 0.08196

As these events are independent and two outcomes, x the no of stink bugs that live to be 4 years old follows a Binomial with p = 0.91804 and n = 2.

a) P(x=2) = 0.8428

b) P(x=8 when n =8) = 0.5045