Let X be a binomial random variable with p=0.6 and n=10. What is P(X > 8) ?

1 Answer
Jul 1, 2017

P(X>8)=0.0463574016

Explanation:

Given that, X is a Binomial Random Variable, with,

parameters, p=0.6, and, n=10, denoted by,

X~~ B(10,0.6).

:. q=1-p=0.4

Knowing that, for X~~B(n,p),

P(X=x)=""_nC_xp^xq^(n-x), x=0,1,2,...,n.

Now, the Reqd. Prob.=P(X>8),

=P(X=9)+P(X=10),

=""_10C_9(0.6)^9(0.4)^1+""_10C_10(0.6)^10 (0.4)^0,

=10(0.6)^9(0.4)+1(0.6)^10(1),

=4(0.6)^9+(0.6)^10,

=(0.6)^9(4.6),

rArr P(X>8)=0.0463574016