MDM4UI

Geometric Distribution: Waiting Times

  1. Tabulate and graph the geometric distributions for X = 0, 1, 2, 3 in the following situations.

a) p = 0.5b) p = 0.2c) p = 0.7

  1. In the repeated rolling of a single die, what is the probability that you will roll a five or a six for the first time on the fourth roll?
  1. If you repeatedly cut a deck of cards, what is the probability that you will cut an ace in fewer than five cuts?
  1. What are the odds against your rolling doubles in fewer than four rolls of two dice? (First calculate the chances, then convert to odds.)
  1. What is the expected number of people you would have to sample to find someone with the same birthday as yours?
  1. If a recent poll indicated that the Hippopotamus party had 9% popular support, what would be the expected number of people that a television interviewer must survey to obtain the opinion of a Hippo supporter?
  1. If 2% of the transactions at a bank are applications for loans, what is the probability that the first loan request on a given day occurs with the tenth customer?
  1. It is estimated that on a daily basis 15% of the customers at a local supermarket use the express checkout. What is the probability that one of the first five customers on a given day uses the express checkout?
  1. If the probability of Michiko getting an A on her math tests is 0.6, what is the probability that a) she will get her first A on the second test?

b) she will get an A on one or more of her first three tests?

10. A production process produces components of which 3 percent are defective.

a) What is the expected number of components produced before a defective one is made?

b) What is the probability that the first defective component will occur within the first five

components off the line?

Answers: 2. 8/813. 0.2744. 125:915. 3646. 107. 0.017

8. 0.5569. a) 0.24b) 0.93610. a) 32b) 0.141