contestada

If X is a binomial random variable associated with a binomial experiment with
μ = E(X) = 54
and
σx = 6,
what are n and p?

Respuesta :

For a binomial distribution over [tex]n[/tex] trials and with success probability [tex]p[/tex], the mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex] ar such that

[tex]\begin{cases}\mu=np\\\sigma=\sqrt{np(1-p)}\end{cases}[/tex]

[tex]6=\sqrt{np(1-p)}\implies np-np^2=36[/tex]
[tex]54=np\implies54-54p=36\implies p=\dfrac13[/tex]
[tex]54=\dfrac n3\implies n=162[/tex]