Question

sampling

• a random sample is a part of a population that is representative of the whole.
• a sample is unbiased if it does not favor one group or part of the population. an unbiased sample may be used to make predictions about data.
• a sample is biased if it favors one group or part of the population. a biased sample should not be used to make predictions about data.

determine if the situations below are biased or unbiased and explain why.

1. a teacher asks the first five students that walk into her room if they prefer getting to class early or late. she concludes that all her students prefer to get to class early.
2. at a convention, each attendee is given a number. a number is randomly selected in a drawing, and the person with that number wins a laptop.
3. two people from each 8th period class are asked what they think the theme of the next dance should use.
4. the newspaper staff surveyed a group of students at a band concert about what their favorite elective is.
5. every 5th person who enters the cafeteria is asked what their favorite food that is being served is.
6. texas tech and oklahoma state university are playing each other in the march madness tournament. to determine which team is favored to, win, a group of 100 students at the texas tech student union center are surveyed.

Explanation:

This is a systematic sampling method (every 5th person) that doesn't favor any group in the cafeteria population, so the sample is representative and unbiased.

The sample consists of students at the Texas Tech student union center, who are likely to favor Texas Tech. This sample favors one group (Texas Tech - supporting students) and is not representative of all relevant individuals (e.g., Oklahoma State fans or neutral observers), so it is biased.

Answer:

(for question 5):
Unbiased