What type of sampling technique was used in each of the following scenarios:

a) (3 pts) Researchers waited outside a bar of interest. They stopped every 10th person

who came out of the bar and asked whether he or she thought drinking and driving was

a serious problem.

b) (3 pts) Hoping to learn what issues may resonate with voters in the coming election, the

campaign director for a mayoral candidate selects one block from each of the city's

election districts. Staff members go there and interview all the residents they can find.

c) (3 pts) A company packaging snack food maintains quality control by randomly selecting

10 cases from each day's production and weighing the bags. Then they open one bag

from each case and inspect the contents.

d) (3 pts) Provincial police set up roadblocks to estimate the percentage of trucks with up-

to-date registration, insurance, and safety inspection stickers.