Biased and Unbiased

A homeowner divides their backyard into 5 sections, and randomly removes soil from sections.

A public library asked every 10th person who entered to name the type of book they were getting.

A hospital wants to open a gym. They ask the night-shift ER staff when they would use the gym.

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

A senator wants to know how she is doing in her position. She sends a survey to 1000 registered voters in her party.

To determine the most popular children’s programs, a television station asks parents to call in and complete a phone survey.

Carlos wants to know the favorite sport of people at his school so he asks his baseball team.

To see who has a computer at home the front office chooses 10 students randomly per grade to ask.

Carlos wants to know the favorite sport of people at his school so he asks his baseball team. What type of sample would this be?

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