A binomial probability experiment is conducted with the given parameters. Compute the probability of x successes in the n independent trials of the experiment.

Question

n=9, p=0.4, x<_3

The probability of x<_3 successes is ?

Answer 1

P(x=0)= .6^9

P(x=1) =9(.4)(.6)^8

P(x=2)=36(.4^2)(.6)^7

P(x-3) = 9C3(.4^3)(.6^6)=84(.064)(.6^6)

add them up to get P(x</=3)