Identify the sampling designs that use voluntary response sampling. Check all that apply.


A pharmaceutical company advertises for subjects to participate in an online survey about insulin pumps for diabetics.

An online poll is created for sports fans to vote on the winner for the Super Bowl.

Each employee is given a mandatory survey to complete about health benefits.

After each customer service call, callers are asked to stay on the line to complete a brief satisfaction survey.

A census taker randomly calls homes to gather data about household income and family demographics.

A used car dealer surveys potential customers about the type of car they are interested in so he can plan his future inventory.