Interactive practice questions
After the government decided to increase the minimum retirement age, a news poll selected a group of people to ask their opinions on the changes.
What kind of people should be represented to avoid sampling bias?
People in the community who have a wide variety of views, even if they are not directly affected by the changes.
People in the community who have a wide variety of views, excluding politicians and policy makers.
Only people in the community who would be directly affected by the changes.
Only people who are employed.
Irene is interested in which students from her school catch public transport. Select whether the following sampling methods are likely to be biased or not.
A political polling company calls $1000$1000 people at home between $4$4pm and $6$6pm on weeknights to find out who they are most likely to vote for in an upcoming election. They publish their numbers based on the responses of only the $450$450 people who answered their call.
Marine biologists want to determine if a local species of fish is growing to a smaller size than it used to. They collect and measure $150$150 of the $450$450 fish known to exist in the area.