Sampling and Bias

Marianne wanted to know students' opinion on the new schedule at school. She places students' names in a container and randomly picks out 20 names. 

• Convenience Sampling
• Systematic Random Sampling
• Simple Random Sampling
• Volunteer response

Why do we randomly select our samples?

• for control
• reduce bias
• so we don't get the same answers from everyone
• to eliminate confounding results

Dylan wants to know how the students at his school rate the cafeteria.  He surveyed his school's basketball team to rate the school cafeteria. Is this a biased sample of the school's population?

• Yes, because it is a convenience survey
• No, the basketball team has the smartest students
• Yes, because it's voluntary survey
• No, he should have asked the football team

Ana wants to know the average student’s opinion of the tardy policy at her school. Which group of students should she survey in order to achieve the most accurate results?

• thirty students who are often tardy
• thirty students who are rarely tardy
• thirty of her friends
• thirty randomly selected students from her school

You want to know what is the most favorite sport of 10th graders at CHS. You ask 10th graders who want to participate to go to the office B Lunch to complete a survey. This is...

• Biased, because it is a convenience sample

• Unbiased

• Biased because it is an interval sample

• Biased because it is a volunteer sample

The population describes:

• The group of people, objects or events being surveyed
• a part of the group being surveyed
• the whole world
• the school

Sam tested every 50th candy bar from the assembly line to make sure there were enough peanuts in each bar.  He found 15% did not have enough peanuts.  How many candy bars do not have enough peanuts if the factory produces 20,000 candy bars?

• 300
• 3,000
• 300,000
• 50

Mrs. Trahan samples her class by selecting 5 girls and 7 boys.  This type of sampling is called?

• Stratified
• Systematic
• Simple
• Cluster

Mrs. Trahan samples her class by selecting every third person on her class list.  Which type of sampling method is this?

• Simple
• Systematic
• Stratified
• Cluster

Mrs. Trahan samples her class by selecting all students sitting at group 1 and group 5 in her classroom.  This sampling technique is called?

• Simple
• Stratified
• Systematic
• Cluster