1. A restaurant leaves a fishbowl on the counter for diners to drop their business cards. Once a month, a business card is pulled out to award one lucky diner with a free meal. Identify which type of sampling is used and why.

2. A test of the effectiveness of a new curriculum could begin by dividing an area by school district, then choosing a school or set number of schools at random and sampling students from each. Identify which type of sampling is used and why.

3. A survey about timekeeping might divide the population by time zone, then take 100 random samples per zone. Identify which type of sampling is used and why.

4. A local TV station conducts an "Instant Poll" to predict the winner in the upcoming mayoral election. Evening news viewers were invited to phone in their votes, with the results to be announced on the late-night news. Based on the phone calls, the station predicted that Joseph Serra would win the election with 52% of the vote. They were wrong: Serra lost, getting only 46% of the vote. This faulty prediction may be the consequence of what kind of bias?