Respuesta :
Answer:
The probability that all five are still good two years later is 0.498.
Explanation:
Let X = number of internet sites that vanishes within 2 years.
The probability of an internet site vanishing within 2 years is: P (X) = p = 0.13.
A paper consists of n = 5 internet references.
The random variable X follows a Binomial distribution with parameters n = 5 and p = 0.13.
The probability mass function of a Binomial distribution is:
[tex]P(X=x)={n\choose x}p^{x}(1-p)^{n-x};\ x=0, 1, 2,3...[/tex]
Compute the probability of X = 0 as follows:
[tex]P(X=0)={5\choose 0}(0.13)^{0}(1-0.13)^{5-0}=1\times 1\times 0.498421\approx0.498[/tex]
Thus, the probability that all five are still good two years later is 0.498.
