Studies show that a randomly selected dollar bill has a 0.9 chance of containing trace amounts of cocaine. Round answers to 4 decimal places (a) Is this situation best modeled by the binomial distribution or Poisson distribution? (b) What is the probability that out of 500 bills, exactly 435 have trace amounts of cocaine? (c) What is the probability that our of 500 bills, more than 425 have trace amounts of cocaine