In a Poisson distribution, μ = .38 (Round your answers to 4 decimal places.) (a)What is the probability that x=1 ? Probability= (b)What is the probability that x>3 ? Probability=

SOLUTION:
Recall the poisson probability formula:
[tex]p(x)=\frac{\mu^xe^{-\mu}}{x!}[/tex]It is given that:
[tex]\mu=0.38[/tex]When x=1, it follows:
[tex]\begin{gathered} p(1)=\frac{(0.38)^1e^{-0.38}}{1!} \\ P(1)=0.2599 \end{gathered}[/tex]For x>3:
[tex]P(x>3)=1-P(x\le3)[/tex]This gives:
[tex]\begin{gathered} P(x>3)=1-(\frac{0.38^0e^{-0.38)}}{0!}+\frac{0.38^1e^{-0.38}}{1!}+\frac{0.38^2e^{-0.38}}{2!}+\frac{0.38^3e^{-0.38}}{3!}) \\ P(x>3)=0.000642 \end{gathered}[/tex]