Find the indicated probability using the geometric or Poisson distribution. Assume that the probability that you will make a sale on any given...

Find the indicated probability using the geometric or Poisson distribution. Assume that the probability that you will make a sale on any given telephone call is 0.21. Find the probability that you will(a.) make your first sale on your fifth call,(b.) make your sale on the first, second or third call, and(c.)do not make a sale on your first three calls.