Question 8.43

12. Based on data from the American Community Survey, a high percentage of U.S. workers drive alone to work (see Tables 8.1 and 8.2, pages 348 and 349). A 2009 survey asked respondents about the number of vehicles they had access to within their household. The results appear below.

Table 8.21: Table 8.9 Results from a 2009 American Community Survey
Workers and Vehicles Frequency
Workers in households with zero vehicles 5, 138, 372
Workers in households exceeds vehicles 12, 357, 761
Workers in households equals vehicles 66, 463, 188
Vehicles exceed workers in households 67, 413, 776
Total 151, 370, 000

391

  1. Assume that the sample fairly represents workers in the United States. Use the sample proportions in each category as probabilities and create a probability model for Workers and Vehicles (round probabilities to three decimal places).
  2. Verify that Rule 2 is satisfied.
  3. Find the probability that there are at least as many vehicles as there are workers in the household. Which probability rule did you use to answer this question?
  4. Find the probability that the workers in the household have access to at least one vehicle. Which probability rule did you use to answer this question?