5. Decide whether the following experiment is a binomial experiment. Explain your answer.

A researcher observes the gender of the next 100 babies born at a local hospital. The boys and girls are equally likely. The random variable represents the number of boys.

2 answers

p boy = .5
p not boy = 1-p boy = .5
sure looks like a binomial experiment to me

lets find the probability of four boys out of ten births for example

P(10,4) = C(10,4) .5^4 * (1-.5)^6

= 10!/[4!(6!)] *(1/16)*(1/64)

= 210 / 1024

= .205
Well, that was fun :)