Suppose that 30% of the population has type A blood.
a) If 8 people are selected at random, what is the probability that at least four of them have type A blood.
b) If 80 donors come to give blood one day, what is the probability that at least forty of them have Type A blood (using the normal approximation)? Explain why this is higher or lower than the answer in part (a).
c) If 20 people come to give blood, what is the probability that at least one of the donors is of Type A?