What is the answer?

Question

In a random sample of 15 people selected from the NPP(Political party),40% favour a new voters' Register.what is the probability that exactly 6 individuals selected from this sample Will favour a new voters' Register.

Answer 1

Those in favour p=0.4, those against 1-p=0.6.

This is a binary situation where (p+(1-p))^15=1, the sum of all probabilities.

The coefficients in the binomial expansion are 1 15 105 ... 105 15 1, a symmetrical pattern. We want 15C6=5005.

The term we need is 5005*p^6(1-p)^9=5005*0.4^6*0.6^9=0.2066 approx or 20.66%.

Comments

Thanks,I had the same answer but I was not 100% sure