In all parts of this problem assume that the samples are representative of the population: A It is well known that, on average, about 7.5% of the population has O-negative blood type They are known as universal donors making this type of blood very important. Suppose that a certain large Red Cross clinic gets 45 visitors in a typical day. What's the probability that exactly 4 of them have O-negative blood. (Hint: this is a binomial situation.) B. Suppose this same clinic advertises a blood drive for a week (Mon-Sat) and that 420 people come in and give blood (1 unit each.) The clinic needs to acquire 29 units of O-neg blood to supply local hospitals. What is the probability that they will get at least the needed amount during this drive