Let X be the number of flaws on the surface of a randomly selected boiler of a certain type and suppose X is a Poisson distributed random variable with parameter μ = 5. Find P(2 ≤ X ≤ 4)

Respuesta :

Answer:

0.40006

Step-by-step explanation:

Let as assume that X is a Poisson distributed random variable with parameter μ = 5.

Poisson distribution Formula:

[tex]P(X=x)=\dfrac{\mu^xe^{-\mu}}{x!}[/tex]

where, μ is mean.

We need to find the value of P(2 ≤ X ≤ 4).

[tex]P(2\leq X\leq 4)=P(X=2)+P(X=3)+P(X=4)[/tex]

[tex]P(2\leq X\leq 4)=\dfrac{5^2e^{-5}}{2!}+\dfrac{5^3e^{-5}}{3!}+\dfrac{5^4e^{-5}}{4!}[/tex]

[tex]P(2\leq X\leq 4)=0.08422+0.14037+0.17547[/tex]

[tex]P(2\leq X\leq 4)=0.40006[/tex]

Therefore the value of P(2 ≤ X ≤ 4) is 0.40006.

Using the Poisson distribution, it is found that P(2 ≤ X ≤ 4) = 0.4001.

What is the Poisson distribution?

In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by:

[tex]P(X = x) = \frac{e^{-\mu}\mu^{x}}{(x)!}[/tex]

The parameters are:

  • x is the number of successes
  • e = 2.71828 is the Euler number
  • [tex]\mu[/tex] is the mean in the given interval.

In this problem, the mean is [tex]\mu = 5[/tex], and:

[tex]P(2 \leq X \leq 4) = P(X = 2) + P(X = 3) + P(X = 4)[/tex]

In which:

[tex]P(X = x) = \frac{e^{-\mu}\mu^{x}}{(x)!}[/tex]

[tex]P(X = 2) = \frac{e^{-5}5^{2}}{(2)!} = 0.0842[/tex]

[tex]P(X = 3) = \frac{e^{-5}5^{3}}{(3)!} = 0.1404[/tex]

[tex]P(X = 4) = \frac{e^{-5}5^{4}}{(4)!} = 0.1755[/tex]

Then:

[tex]P(2 \leq X \leq 4) = P(X = 2) + P(X = 3) + P(X = 4) = 0.0842 + 0.1404 + 0.1755 = 0.4001[/tex]

Hence P(2 ≤ X ≤ 4) = 0.4001.

More can be learned about the Poisson distribution at https://brainly.com/question/13971530