Answer:
0.001687 = 0.1687% probability that no more than 1 vessel transporting nuclear weapons was destroyed.
Step-by-step explanation:
The vessels are destroyed and then not replaced, which means that the hypergeometric distribution is used to solve this question.
Hypergeometric distribution:
The probability of x successes is given by the following formula:
In which:
x is the number of successes.
N is the size of the population.
n is the size of the sample.
k is the total number of desired outcomes.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
In this question:
Fleet of 18 means that ![N = 18](https://tex.z-dn.net/?f=N%20%3D%2018)
9 are carrying nuclear weapons, which means that ![k = 9](https://tex.z-dn.net/?f=k%20%3D%209)
9 are destroyed, which means that ![n = 9](https://tex.z-dn.net/?f=n%20%3D%209)
What is the probability that no more than 1 vessel transporting nuclear weapons was destroyed?
This is:
![P(X \leq 1) = P(X = 0) + P(X = 1)](https://tex.z-dn.net/?f=P%28X%20%5Cleq%201%29%20%3D%20P%28X%20%3D%200%29%20%2B%20P%28X%20%3D%201%29)
In which
Then
![P(X \leq 1) = P(X = 0) + P(X = 1) = 0.000021 + 0.001666 = 0.001687](https://tex.z-dn.net/?f=P%28X%20%5Cleq%201%29%20%3D%20P%28X%20%3D%200%29%20%2B%20P%28X%20%3D%201%29%20%3D%200.000021%20%2B%200.001666%20%3D%200.001687)
0.001687 = 0.1687% probability that no more than 1 vessel transporting nuclear weapons was destroyed.