Quiz: Conditional Probability


In a promotion at a store, each customer gets a chance to randomly draw a ticket from a box. There are 100 tickets. 20 tickets say “Winner!” and 80 tickets say “Sorry. Try again next time.” Assume two customers play and that the ticket is NOT replaced after the first customer plays. Use this data for questions 1 through 4.


In a city where it rains frequently, records have been kept and relative frequencies have been used to estimate these probabilities. The probability that rain is predicted on a day is 0.2. The probability that it actually rains on a day that rain is predicted is 0.9. The probability that it actually rains on a day that rain is not predicted is 0.3. Use this data for questions 5 through 9.