Bias or Non Bias
Essential Question:
(606.5.3)How can you determine
whether or not a sample is biased?
Biased Sample: this is a sample that is not representative of the population
from which it is selected
Random: choosing a selection of people to survey that do not belong to a specific group
A researcher wants to know which city United States residents like to visit the most. The researcher surveyed 200 people from southern California. The survey question and results are shown in the graph.
The Question: Which city do you like to visit the most: Boston, Chicago, Dallas, New York, or San Diego
The researcher claimed that people like to visit San Diego most. Is this claim valid?
San Diego60%
Dallas 20%Boston 5%
Chicago 5%
New York 10%
A survey was given about the best school lunch served in the cafeteria. The Cafeteria manager surveyed the LMS employees and made phone calls to parents to determine what the best lunch is.
a)Is this sample biased?b)Why or Why not?c) What should be done differently so that it is
unbiased?
The governor of Tennessee was trying to come up with a new program for middle schools in the area. He wanted to know what middles school students’ favorite hobby is. He decided to call 600 random families in the Murfreesboro area to conduct a survey to find out.
a)Is this sample biased?b)Why or Why not?c) What should be done differently so that it is unbiased?
LMS is buying new equipment for the classrooms and were trying to decide how to spend the money. A survey was given to help make a decision. Which group would most likely give a biased answer?
a)Parents of studentsb)Math teachersc) Teachers from all subject areasd)Random students in the auditorium.
The NFL was trying to decide who has the best fans. The NFL decided to conduct a survey to determine their answer. Which group should be surveyed so that the sample is not biased?
a)Titans cheerleadersb)Only people who live in Texasc) Major league baseball playersd)Football fans throughout the country.
A candidate for mayor wants to poll voters to see how well her campaign is doing. She plans to post signs asking people to call the pollsters with their opinions. Which best explains why the sample of people who call the pollsters may be biased?
A) Callers may not tell the truthB) The responders are unlikely to be a random sample
of votersC) There may be too many female callersD) People may not see the signs
The yearbook committee wants to know whether students think there should be more pages in the music section. Which method of sampling is least likely to produce a biased sample?
A) Survey 50 students in the lunch lineB) Have each student working on the music
section survey 10 friendsC) Survey students in the school chorusD) Survey students performing in the school
musical
A real estate agent wants to learn about apartment rental fees in her town. Which is the best method of collecting unbiased data?
A) Call 20 landlords selected at random and ask them how much rent they charge
B) Use the real estate ads to find the rent for 20 apartments
C) Research rents in a quiet neighborhood near the park and shops
D) Find out the rent on all the units in the largest apartment building in town.
A museum director wants to know which types of exhibits will attract more people. The director surveyed 100 visitors on a Sunday afternoon. Why is the data collected in this survey biased?
A) The director needs to sample the entire population of potential visitors
B) The director should survey only people visiting the newest exhibit.
C) The sample is not large enough. The director should survey more people.
D) The people surveyed are already at the museum. The director needs to survey people who do not go to the museum.
TICKET OUT• Write your answers on your index card• Stand up when finished
1. A company wants to survey teenagers to find out if they have heard of the company’s new clothing brand. Which sample group would most likely to be biased?
a) Teens from several different communitiesb) Teens of a wide range of agesc) Teens from different areasd) Teens who shop at a certain store
