Representative Sample Scenarios Are these samples representative?
1. To determine the percentage of teenage girls with long hair, Teen magazine
published a mail-in questionnaire. Of the 500 respondents, 85% had hair shoulder
length or longer (USA Today, July 1, 1985).
2. A college psychology professor needs subjects for a research project to determine
which colors average American adults find restful. From the list of all 743
students taking introductory psychology at her school, she selects 25 students
using a random number table.
3. To evaluate the reliability of cars owned by its subscribers, Consumer Reports
magazine publishes a yearly list of automobiles and their frequency-of-repair
records. The magazine collects the information by mailing a questionnaire to
subscribers and tabulating the results from those who return it.
4. Oranges from an orchard need to be samples to see if they are sweet enough for
juice. The orchard has 25,000 orange trees. Each tree has at least 500 oranges.
Claire decides to randomly choose 800 trees and test one orange from each tree.
5. For a survey of student opinions about school athletic programs, a member of the
school board obtains a sample of students by listing all students in the school and
using a random number table to select 30 of them. Six of the students say that
they don’t have time to participate, and they are eliminated from the sample.
6. There are fifteen boys and fifteen girls in a math class. Each student’s
name is placed in a hat and the names are thoroughly mixed. Seven names are
drawn and all names correspond to the boys in the class.