Biased Unbiased Sample

A researcher selects a sample of 100 students from a local high school by choosing the first 100 students who enter the school one morning. Is this sample likely to be biased or unbiased?

• Biased

• Unbiased

To understand the average height of adults in a city, a surveyor randomly selects 500 adults from the entire adult population of the city. Is this sample likely to be biased or unbiased?

• Biased

• Unbiased

A high school is going to have a party for their graduating seniors. They want to serve food that most of the seniors like. They pick 25 random names from a hat and survey those students. Is this a biased sample or unbiased sample?

• Biased Sample

• Unbiased Sample

To determine how many students plan to attend the school musical, Maria surveys 100 random people in the hallway.

• Biased

• Unbiased

4. A company makes DVDs and randomly selects 25 from 1500 to test them to see if they work.

• Biased

• Unbiased

Identify the sample method used and whether it is biased or unbiased.

A member of the cafeteria staff asks every fifth student leaving the cafeteria to rank 5 entrees from most favorite to least favorite.

• Biased

• Unbiased

• Voluntary Response

• None of the above

Mrs. Thompson wants to find out what percent of the students did their homework last night. They select a random sample of 100 students and send an email to each of them asking if they did all of their homework last night. Of the 40 responses, 36 of the students (90%) said they did all of their homework last night. How will the actual homework percent differ from what the principal thinks based on these results?

• Actual homework percent will be higher than what the principal thinks.

• Actual homework percent will be lower than what the principal thinks.

• The principal's estimate will be very close.

Boy Scout Peter M. wants to know the proportion of people in his neighborhood who support the Boy Scouts. He takes a random sample of 30 homes and visits them dressed in his uniform. He finds that 28 out of 30 neighbors support the Boy Scouts. Select the statement below that is true.

• His survey is biased and any inferences are invalid.

• His survey is biased and any inferences are valid.

• His survey is unbiased and any inferences are invalid.

• His survey is unbiased and any inferences are valid.

Mr. Thrasher wants to know how the students at Cedar Bluff rate the cafeteria. He surveyed the hungry baseball team after practice last week to rate the school cafeteria. Is this a biased sample of the school's population?

• Yes, because it only asked one group of students

• No, the baseball team has the smartest students

• Yes, because it's voluntary survey

• No, the baseball team are good food critics

To determine how many homes in his neighborhood plan to hand out candy on Halloween, Daniel chooses one street at random and surveys each household on that street.

• Biased

• Unbiased