Unit 8, Lesson 3
Randomness in Groups
Algebra 2
Practice
Problem 1
Andre is in the band, and he is conducting an experiment to determine if high school students find listening to classical music or listening to the sounds of the ocean more calming. He randomly selects five students from the band to listen to classical music. He then randomly selects five people from the swim team to listen to the sounds of the ocean. What is problematic about the way that Andre selected his groups?
Problem 2
You want to survey 20 of the 150 ninth graders to get their opinion on the school’s new schedule. Which of these methods is most likely to lead to a sample that is the most representative of the 150 ninth graders?
Choose 20 ninth graders from your first period class.
Choose the first 20 ninth graders from an alphabetical list.
Select 20 students at random from the ninth grade.
Select 5 students at random from each of ninth, 10th, 11th and 12th grade.