Random or Representative Sample

I drew 10 names from a hat containing the names of every student that I teach, what type of sample have I taken?

• A random sample.

• A biased sample.

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

• Biased

• Unbiased

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 estimate the number of students in a high school who ride the school bus. Which sample is best?

• 4 students in the hallway

• All students in the marching band

• 50 seniors at random

• 100 students at random during lunch

Which one is the sample?

• All books in library

• 10 library books

Choose the best sample.

• Sample A

• Sample B

Choose the best sample.

• Sample A

• Sample B

Which of the following is NOT needed in order to be considered an unbiased sample?

• Selected at random

• Representative of the entire population (everyone has a chance of being chosen)

• Representative of at least half of the population

• Large enough to provide accurate data

An environmental advocacy group wants to know how residents intend to vote on a proposal to reduce bus service to certain neighborhoods in the city. They decide to conduct a survey.

Which describes a representative sample of the population for the situation?

• a randomly selected group of members at a local gardening club

• a randomly selected group of residents from the city’s voter registration records

• a randomly selected group of workers at a factory that employs a large percentage of the city

• a randomly selected group of residents in the neighborhoods affected by the proposal

The counselors at a camp are scheduling activities for family visitation day. They decide to conduct a survey to determine which activities campers would most like to share with their families. Which describes a method for getting a sample that is both representative and random?

• During the dinner hour, announce that any camper interested in doing so can collect and complete a survey.

• During camp free time, ask every fifth camper in the arts and crafts hall to complete a survey.

• During morning roll call, ask every tenth camper to complete a survey.

• During camp free time, ask all campers down at the lake to complete a survey.