Answer:
0.7588 = 75.88% probability that more than 1 vessel transporting nuclear weapons was destroyed
Step-by-step explanation:
The vessels are destroyed without replacement, 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:
![P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}](https://tex.z-dn.net/?f=P%28X%20%3D%20x%29%20%3D%20h%28x%2CN%2Cn%2Ck%29%20%3D%20%5Cfrac%7BC_%7Bk%2Cx%7D%2AC_%7BN-k%2Cn-x%7D%7D%7BC_%7BN%2Cn%7D%7D)
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.
![C_{n,x} = \frac{n!}{x!(n-x)!}](https://tex.z-dn.net/?f=C_%7Bn%2Cx%7D%20%3D%20%5Cfrac%7Bn%21%7D%7Bx%21%28n-x%29%21%7D)
In this question:
Fleet of 17 means that ![N = 17](https://tex.z-dn.net/?f=N%20%3D%2017)
4 are carrying nucleas weapons, which means that ![k = 4](https://tex.z-dn.net/?f=k%20%3D%204)
9 are destroyed, which means that ![n = 9](https://tex.z-dn.net/?f=n%20%3D%209)
What is the probability that more than 1 vessel transporting nuclear weapons was destroyed?
This is:
![P(X > 1) = 1 - P(X \leq 1)](https://tex.z-dn.net/?f=P%28X%20%3E%201%29%20%3D%201%20-%20P%28X%20%5Cleq%201%29)
In which
![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)
So
![P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}](https://tex.z-dn.net/?f=P%28X%20%3D%20x%29%20%3D%20h%28x%2CN%2Cn%2Ck%29%20%3D%20%5Cfrac%7BC_%7Bk%2Cx%7D%2AC_%7BN-k%2Cn-x%7D%7D%7BC_%7BN%2Cn%7D%7D)
![P(X = 0) = h(0,17,9,4) = \frac{C_{4,0}*C_{13,9}}{C_{17,9}} = 0.0294](https://tex.z-dn.net/?f=P%28X%20%3D%200%29%20%3D%20h%280%2C17%2C9%2C4%29%20%3D%20%5Cfrac%7BC_%7B4%2C0%7D%2AC_%7B13%2C9%7D%7D%7BC_%7B17%2C9%7D%7D%20%3D%200.0294)
![P(X = 1) = h(1,17,9,4) = \frac{C_{4,1}*C_{13,8}}{C_{17,9}} = 0.2118](https://tex.z-dn.net/?f=P%28X%20%3D%201%29%20%3D%20h%281%2C17%2C9%2C4%29%20%3D%20%5Cfrac%7BC_%7B4%2C1%7D%2AC_%7B13%2C8%7D%7D%7BC_%7B17%2C9%7D%7D%20%3D%200.2118)
Then
![P(X \leq 1) = P(X = 0) + P(X = 1) = 0.0294 + 0.2118 = 0.2412](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%200.0294%20%2B%200.2118%20%3D%200.2412)
![P(X > 1) = 1 - P(X \leq 1) = 1 - 0.2412 = 0.7588](https://tex.z-dn.net/?f=P%28X%20%3E%201%29%20%3D%201%20-%20P%28X%20%5Cleq%201%29%20%3D%201%20-%200.2412%20%3D%200.7588)
0.7588 = 75.88% probability that more than 1 vessel transporting nuclear weapons was destroyed