The American Housing Survey reported its findings about the principal means of transportation to work by worker in Washington, DC, during the year of 2001.

Means of Transportation Number (thousands)

All workers 120,191 Automobile 105,586 Drives self 93,942 Carpool 11,644 2-person 9,036 3-person 1,635 4 person 973 Public transportation1 5,627 Taxicab 133 Bicycle or motorcycle 847 Walks only 3,408 Other means2 1,049 Works at home 3,401 NOTE: Principal means of transportation refers to the mode used most often by individual.

1. Public transportation refers to bus, streetcar, subway, or elevated trains.

2. Other means include ferryboats, surface trains, and van service.

Source: U.S. Department of Housing and Urban Development, American Housing Survey, Washington, DC, 2001, http://www.infoplease.com/ipa/A0908113.html

a. The column total is not included because they would be meaningless values. Examine the table and explain why.

One person is to be selected and asked additional questions as part of this survey. If that person is selected at random, find the probability for each of the following events.

b. Person selected is a member of a two-person carpool.

c. Person selected is a member of a two-person carpool given that the person carpools.

d. Person selected does not arrive by car.

e. Person selected uses public transportation knowing that person does not use an automobile.