Question: Suppose that 30% of all drivers stop at an intersection having flashing red lights when no other cars are visible. Of 15 randomly selected drivers coming to an intersection under these conditions, let X denote the number of those who stop.
(a) The random variable X is (choose one)
(i) binomial
(ii) hypergeometric
(iii) negative binomial
(iv) Poisson.
(b) Give the expected value and variance of X.
(c) Find the probabilities P(X = 6) and P(X ≥ 6). You may use R commands.