Bias in Surveys

_______ is the entire group of objects or individuals considered for a survey.

• Sample
• Population
• Random Sample
• Quartile

_______ is a part of a group being surveyed.

• Sample
• Population
• Random Sample
• Quartile

A school randomly chose ten English teachers and asked them which type of juice their students would prefer. Which reason best shows why this sample is biased?

• The sample didn't include students.
• The sample is too small.
• The sample can only be accurate if each teacher is included in the sample

Interview every 15th student who enters the school in the morning.

• simple random

• population

• systematic

• convenience

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

A teacher wants to know the average time spent doing homework by the students in her class of 20 girls and 5 boys.
She selects the five closest to her desk.

• simple random
• representative
• Convenience
• Systematic 

Source of bias that occurs when you ask people who are EASY to ask

• Response Bias
• Convenience Sampling
• Nonresponse
• Voluntary Response

Which sampling methods reduces bias?

• Simple Random

• Stratified

• Cluster

• Convenience

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

A recent survey found that out of 400 random American adults, 89% pay their bills on time. The margin of error in this survey was 2%. What is the interval of values in which the truth is likely found?

• 89% - 91%

• 87% - 89%

• 87% - 91%

• 388 - 402