Originally Posted by

**lra11** the random variable x has a binomial distribution with n=6 and p=0.2

calculate P(X=6), I have tried this question several times and suspect it it not that difficult however I keep coming out with the wrong answer.

Is it 6choose6 x 0.2^6 x 0.8^0 ?? Mr F says: Yes. And that obviously simplifies to 0.2^6 ......

also how would I go about calculating

Given that Z~B(9,0.45) calculate P(Z=4 or 5) Mr F says: Pr(Z = 4) + Pr(Z = 5). Plug the numbers into the usual formula to solve for each probability.

Any help would be great thanks