prob. of complications is .30; prob <=2 of 4 have complicati

Should be easy? I just can't seem to get it.

With a certain medical procedure, the probability that a person will have complications is .30. If 4 randomly selected patients have this procedure, what is the probability that 2 or fewer will have complications?

I tried to make a table but get lost with the .30 : 1 2 3 4 how do I decide the others? I have .70 left to distribute to the other 3? .30

Maybe I am over thinking.

Re: Should be easy?

Do you know about the binomial distribution?

Re: Should be easy?

I need to use the binomial table?

Re: Should be easy?

\(\displaystyle \[\sum\limits_{k = 0}^2 {{4 \choose k}\left( {0.3} \right)^k \left( {0.7} \right)^{4 - k} }\)