Work sheet #10 STA 2023

Identify which type of sampling is used for each of the following:

(Random, Systematic, Stratified, Cluster, or Convenience)

1) The Gallop Organization plans to conduct a poll of New York City residents with the “212” area code. Computers are used to generate phone numbers that are automatically dialed.

2) A marketing expert for MTV is planning a survey in which 500 people will be randomly selected from each age group 10-19, 20-29, and so on.

3) An ABC news reporter polls people as they pass him on the street.

4) A General Motors researcher has partitioned all registered cars into categories of sub-compact, compact, mid-size, intermediate, and full-size. She is surveying 200 randomly selected car owners from each category.

5) A Johns Hopkins University researcher surveys all cardiac patients in each of 50 randomly selected hospitals.

6) The Commissioner of Jurors obtains a list of 42,763 car owners and polls every 100^th name on that list.

7) A college conducts a study of student drinking by randomly selecting 10 different classes and interviewing all of the students in each class.

8) A college conducts the above study by randomly selecting 3 students from every class.

9) A lobbyist for the tobacco industry obtains a sample of members of Congress by writing the 535 names on individual index cards, putting them in a box, and selecting 50 names.

10) An economist conducts a survey of 150 randomly selected workers from each of these categories: less than high school diploma, high school diploma, more than high school diploma.

11) A prison guard surveys all the prisoners in the cell block where he works.

12) A sobriety checkpoint where police stopped every fifth driver.

13) CNN does an exit poll in which 100 voting precincts are randomly selected and all voters who enter each are interviewed.

14) A complete list of stock-holders is compiled and every 500^th name is selected.

15) A list of stock-holders is compiled by number of shares owned: those owning over 1000 shares, those owning 500-999, those owning 100-499, and those owning fewer than 100 shares. Then 50 names are randomly selected from each list.

16) A sample of 50 stock-brokers is randomly selected and all their clients are surveyed.

17) Stock-holders are listed by zip-code and 5 are randomly selected from each zip-code.

18) Each stock-holder is assigned a computer-generated number and then a random number generator selects a sample of 1000 from the list to be surveyed.