Answer:
[tex]P(X=6)=(100C6)(0.085)^6 (1-0.085)^{100-6}=0.1063[/tex]
Then the probability that exactly 6 bridges in the sample are structurally deficient is 0.1063 or 10.63%
Step-by-step explanation:
Let X the random variable of interest "number of bridges in the sample are structurally deficient", on this case we now that:
[tex]X \sim Binom(n=100, p=0.085)[/tex]
The probability mass function for the Binomial distribution is given as:
[tex]P(X)=(nCx)(p)^x (1-p)^{n-x}[/tex]
Where (nCx) means combinatory and it's given by this formula:
[tex]nCx=\frac{n!}{(n-x)! x!}[/tex]
And we want to find this probability:
[tex] P(X=6)[/tex]
And if we use the probability mass function and we replace we got:
[tex]P(X=6)=(100C6)(0.085)^6 (1-0.085)^{100-6}=0.1063[/tex]
Then the probability that exactly 6 bridges in the sample are structurally deficient is 0.1063 or 10.63%
