Question

to find how high school students feel about hot lunches, adam walks to the nearest high school and gives a survey postcard to every twentieth student that enters the building. he asks the students to mail the postcard in if they choose to participate in the study.
why might the method used be biased?
☐ asking every twentieth student does not accurately represent the student population.
☐ it is likely that student opinions in one particular high school do not accurately represent the opinions of all high school students.
☐ students that take the time to complete the survey and mail it in probably feel strongly about hot lunches.

Explanation:

• Option 1: Sampling every twentieth student is a form of systematic sampling. If the population (students entering the building) is randomly ordered, this method can be a valid way to get a representative sample. So, this option is incorrect.
• Option 2: The survey is about "high - school students" in general. Sampling only from one high school means the sample is not representative of the entire population of high - school students. Different high schools may have different lunch programs, student demographics, etc.
• Option 3: When it's a voluntary response (students mail in if they choose), those with strong opinions (either positive or negative) about hot lunches are more likely to respond. This creates a bias as the sample will over - represent those with strong feelings.

Answer:

B. It is likely that student opinions in one particular high school do not accurately represent the opinions of all high school students.
C. Students that take the time to complete the survey and mail it in probably feel strongly about hot lunches.