Random, Representative and Biased Samples

Question 1

A park manager estimates this week's visitors' satisfaction by surveying 200 visitors chosen with random ticket numbers at all entrances. How should this sample be classified?

Accepted Answer

likely representative, because random ticket numbers across all entrances can include any visitor

Answer

biased, because a ticket-number sample can only reach visitors leaving through the main gate

Answer

biased, because visitors choose themselves online

Answer

likely representative, because 200 responses are always enough

Question 2

Student council surveys only students in the first lunch line to estimate all seventh graders' favorite lunch. How should this sample be classified?

Accepted Answer

biased, because one lunch line may not represent all seventh graders

Answer

likely representative, because the first lunch line is the longest one

Answer

likely representative, because the students are in seventh grade

Answer

biased, because student council members asked the questions instead of teachers

Question 3

A newspaper mails surveys to 100 randomly selected registered voters to estimate all town adults' support for a bus route. How should this sample be classified?

Accepted Answer

biased, because registered voters do not include all town adults

Answer

likely representative, because the voters are selected at random

Answer

likely representative, because adults answer the survey

Answer

biased, because mailed surveys are never representative

Question 4

A principal uses a random number generator on the full student ID list to ask about all students' phone policy opinions. Classify the sample.

Accepted Answer

likely representative, because every student ID on the full list can be chosen

Answer

biased, because students who feel strongly about the phone policy are the ones who answer an invitation

Answer

biased, because only students with phones can answer

Answer

likely representative, because the principal chose the topic

Question 5

A coach asks the basketball team after practice to estimate all students' favorite sport. What classification fits the sample?

Accepted Answer

biased, because basketball players are more likely to favor basketball than all students are

Answer

likely representative, because the basketball team draws its players from every grade in the school

Answer

likely representative, because the coach asked in person

Answer

biased, because the sample is chosen randomly

Question 6

A library randomly selects account numbers from its complete membership database to estimate all members' ebook use. How should this sample be classified?

Accepted Answer

likely representative, because the random sample comes from the complete member list

Answer

biased, because ebook users are the only members listed

Answer

biased, because the membership database records only the members who have borrowed an ebook

Answer

likely representative, because libraries have many books

Question 7

A restaurant asks only customers buying dessert on Friday night to estimate all customers' favorite dessert. What classification fits the sample?

Accepted Answer

biased, because Friday dessert buyers may not match all restaurant customers

Answer

likely representative, because every person asked is a restaurant customer

Answer

likely representative, because a busy Friday night brings in customers of every kind the restaurant serves

Answer

biased, because the restaurant asked customers in person instead of online

Question 8

A teacher chooses every 8th name, after a random start, from the seventh-grade roster to ask about homework time. Classify the sample.

Accepted Answer

likely representative, because a systematic sample from the full roster can cover the grade fairly

Answer

biased, because counting off by 8 through a roster lands on students seated together in one class

Answer

biased, because choosing every 8th name is not a random method

Answer

likely representative, because any sample taken from a class roster is representative

Question 9

A mayor surveys households at the recycling center to estimate all households' recycling habits. How should this sample be classified?

Accepted Answer

biased, because recycling-center visitors likely recycle more than all households

Answer

likely representative, because every person surveyed lives in a town household

Answer

likely representative, because the recycling center serves households from every part of the town

Answer

biased, because the survey was given on a weekday

Question 10

A nurse randomly chooses 20 students from each grade roster to estimate all school students' sleep hours. What classification fits the sample?

Accepted Answer

likely representative, because random students are chosen from each grade roster

Answer

biased, because the students who sleep least are the ones most willing to answer a nurse

Answer

biased, because 20 students can never be enough

Answer

likely representative, because nurses know health facts

Question 11

An online game company counts only fan forum comments to estimate all players' opinions about a new level. How should this sample be classified?

Accepted Answer

biased, because forum commenters are self-selected and may be unusually interested

Answer

likely representative, because the company read every comment on the forum

Answer

likely representative, because the fan forum is open to every player who bought the game

Answer

biased, because players in other countries cannot post on the forum

Question 12

At each ride, a park surveys every 20th person leaving all day to estimate riders' wait-time satisfaction. Classify the sample.

Accepted Answer

likely representative, because the method samples riders from each ride throughout the day

Answer

biased, because every 20th person is never random

Answer

biased, because the riders who waited longest are the ones still leaving late in the day

Answer

likely representative, because amusement parks are popular

Question 13

The cafeteria asks only students eating cafeteria breakfast to estimate all students' favorite breakfast. What classification fits the sample?

Accepted Answer

biased, because students who eat cafeteria breakfast may prefer different foods than all students

Answer

likely representative, because the cafeteria asked every breakfast eater, not just a few

Answer

likely representative, because the cafeteria serves breakfast to students from every grade in the school

Answer

biased, because students answered before their classes started

Question 14

The math department draws 5 names at random from each seventh-grade math class to estimate calculator use. Classify the sample.

Accepted Answer

likely representative, because each math class contributes randomly chosen students

Answer

biased, because the students drawn from a math class list are the ones who already own a calculator

Answer

biased, because 5 students from each class is too few to count

Answer

likely representative, because the students are asked during math class

Question 15

A museum asks only gift shop customers to estimate all visitors' favorite exhibit. How should this sample be classified?

Accepted Answer

biased, because gift shop customers are only a subset of all museum visitors

Answer

likely representative, because most museum visitors stop at the gift shop

Answer

likely representative, because gift shop customers have already seen the exhibits

Answer

biased, because the museum asked visitors to name only one favorite

Question 16

A district randomly selects 300 parent contacts from the full directory to estimate all parents' internet access. What classification fits the sample?

Accepted Answer

likely representative, because contacts are randomly chosen from the full parent directory

Answer

biased, because internet access is not a school issue

Answer

biased, because the parents who answer a district survey tend to be the ones with the fastest connection

Answer

likely representative, because 300 is always the perfect sample size

Question 17

A counselor asks only advanced art students to estimate all seventh graders' favorite elective. What is the main source of bias?

Accepted Answer

it overrepresents students who already chose advanced art

Answer

it leaves out students who take advanced art

Answer

it overrepresents students who dislike art electives

Answer

it overrepresents students who have not chosen an elective yet

Question 18

A town asks dog park visitors to estimate all residents' pet ownership. What is the main source of bias?

Accepted Answer

it overrepresents residents who own or spend time with dogs

Answer

it leaves out residents who own dogs

Answer

it overrepresents residents who own no pets but walk through the dog park anyway

Answer

it overrepresents residents who own only cats

Question 19

A store surveys morning shoppers to estimate all customers' opinions about later evening hours. What is the main source of bias?

Accepted Answer

it overrepresents customers who shop in the morning

Answer

it overrepresents customers who shop in the evening

Answer

it leaves out customers who shop in the morning

Answer

it overrepresents customers who only shop online

Question 20

An app uses only voluntary pop-up responses to estimate all users' satisfaction. What is the main source of bias?

Accepted Answer

it overrepresents users motivated enough to respond voluntarily

Answer

it leaves out users who choose to answer pop-ups

Answer

it overrepresents users who have no opinion about the app one way or the other

Answer

it overrepresents users who close pop-ups without reading them

Question 21

A principal asks only students with perfect attendance to estimate all students' reasons for absences. What is the main source of bias?

Accepted Answer

it excludes students who have actually been absent

Answer

it excludes students who never miss school

Answer

it overrepresents students who are often absent

Answer

it excludes students who arrive on time every day

Question 22

A bus company surveys riders on one route to estimate crowding on all routes. What is the main source of bias?

Accepted Answer

it overrepresents conditions on that one bus route

Answer

it overrepresents riders from every route equally

Answer

it leaves out riders on that one route

Answer

it overrepresents the least crowded routes in the city

Question 23

A youth league asks only the winning team to estimate all players' opinions about tournament rules. What is the main source of bias?

Accepted Answer

it overrepresents players whose team benefited from the tournament

Answer

it leaves out players on the winning team

Answer

it overrepresents players from every team equally

Answer

it overrepresents players whose team lost under the rules

Question 24

A website surveys visitors with internet access to estimate all households' internet speeds. What is the main source of bias?

Accepted Answer

it excludes households with no internet or very poor internet access

Answer

it excludes the households whose internet service already works well enough to load a website

Answer

it overrepresents households with slow internet

Answer

it overrepresents households with no internet service

Question 25

A theater asks customers leaving a 3-D movie to estimate all customers' favorite movie type. What is the main source of bias?

Accepted Answer

it overrepresents customers who chose a 3-D movie

Answer

it leaves out customers who chose a 3-D movie

Answer

it overrepresents customers from every screen equally

Answer

it overrepresents customers who prefer 2-D movies

Question 26

A teacher asks only the front row to estimate the whole class's opinion about room temperature. What is the main source of bias?

Accepted Answer

it overrepresents students in one part of the room

Answer

it leaves out the students sitting in the front row

Answer

it overrepresents students from every seat equally

Answer

it overrepresents students in the back of the room

Question 27

A city asks homeowners at a property-tax meeting to estimate all residents' views on park funding. What is the main source of bias?

Accepted Answer

it overrepresents homeowners who attend a tax meeting

Answer

it overrepresents renters who skipped the meeting

Answer

it leaves out homeowners who attend tax meetings

Answer

it overrepresents residents who use the parks most

Question 28

A company surveys only night-shift employees to estimate all employees' lunch menu preferences. What is the main source of bias?

Accepted Answer

it overrepresents workers whose schedules differ from lunch-shift workers

Answer

it overrepresents employees who never work nights

Answer

it overrepresents the customers who buy lunch in the company cafeteria each day

Answer

it overrepresents employees from every shift equally

Question 29

A surveyor uses only the first 20 returned forms to estimate all seventh graders' screen time. What is the main source of bias?

Accepted Answer

it overrepresents students who returned the survey quickly

Answer

it overrepresents students who returned the survey late

Answer

it leaves out students who returned the survey first

Answer

it overrepresents students who did not return a form

Question 30

A coach asks injured athletes in the trainer's room to estimate the whole team's view of practice difficulty. What is the main source of bias?

Accepted Answer

it overrepresents athletes who are injured

Answer

it leaves out athletes who are injured

Answer

it overrepresents athletes who are not injured

Answer

it overrepresents the whole team equally

Question 31

A school needs a sample to estimate all seventh graders' preferred field trip. Which plan is most representative?

Accepted Answer

randomly select names from the full seventh-grade roster

Answer

ask the students entering the art class that meets after lunch

Answer

randomly select names from one seventh-grade homeroom

Answer

ask the first table in one math class

Question 32

For all households' water conservation habits, what town survey plan gives the least biased estimate?

Accepted Answer

randomly choose addresses from the town utility account list

Answer

ask the shoppers buying garden hoses at the hardware store

Answer

randomly choose addresses from the town's newest neighborhood

Answer

ask neighbors on one block

Question 33

A website is estimating subscribers' preferred newsletter length. How should it choose a representative sample?

Accepted Answer

use a random generator to pick subscriber IDs from the full list

Answer

ask only the subscribers who leave comments on the newsletter page

Answer

use a random generator to pick IDs from subscribers who joined this year

Answer

ask the website staff to answer

Question 34

A coach needs opinions from all players about practice time. What sampling plan best represents the players?

Accepted Answer

randomly pick names from every team roster

Answer

ask only the varsity starters

Answer

survey only players who arrive first

Answer

randomly pick names from the varsity roster only

Question 35

To estimate all patrons' favorite book genre, how should a library choose its sample?

Accepted Answer

draw random library card numbers from the full patron database

Answer

ask the patrons standing in the mystery aisle on a weekday afternoon

Answer

draw random library card numbers from patrons who visited this week

Answer

ask the checkout line on Saturday morning

Question 36

A district is surveying parents about bus safety. Which plan is most likely to represent all parents?

Accepted Answer

randomly select parent contacts from the district directory

Answer

randomly select parent contacts from one school's directory

Answer

survey the adults waiting at the bus stop nearest the district office

Answer

post a link and use volunteer responses

Question 37

A teacher wants an estimate of the entire grade's homework minutes. What sample should the teacher choose?

Accepted Answer

random students from all homeroom lists in the grade

Answer

students in one honors class

Answer

the students who stay for homework tutoring after school each week

Answer

the first ten students in one class

Question 38

A youth center estimates members' skate park use. Which sampling plan is most likely representative?

Accepted Answer

randomly choose member numbers from the full membership list

Answer

ask only members carrying skateboards

Answer

survey the members waiting by the skate park door on a Saturday morning

Answer

ask the oldest members only

Question 39

For shoppers' preferred store hours, what mall sampling plan should minimize bias?

Accepted Answer

randomly select receipts from different days and times

Answer

ask only the shoppers who come to the mall on a Saturday afternoon

Answer

survey only store employees' friends

Answer

ask shoppers just before closing time

Question 40

A science club estimates all school students' recycling opinions. Which plan best uses random sampling?

Accepted Answer

use a random number generator on the full school roster

Answer

ask only science club members

Answer

survey the students standing near the recycling bins outside the cafeteria

Answer

ask one lunch table near the door

BLASTROOM

BLASTROOM

BLASTROOM

Random, Representative and Biased Samples

Ways to Play

Device Games: Students play on their phones

Blast Go

Zombie Escape

Avalanche

Maze Blast

Cave Climb

Blast Out

Mystery Auction

Tour Guide

Food Truck Rush

Tug of War

Alien Blast

Glacier Rush

Board Games: Teacher-led, projected to the class

Like what you see?

Bug Blast

BlastRace

BlastQuiz

BlastBoard

Seek & Destroy

Mystery Blast

Checkers

Texas Hold 'Em

Da Bomb

Castle Siege

Hot Potato

Market Mayhem

King of the Hill

Bank Heist

Top Corner

Random, Representative and Biased Samples

Ways to Play

Device Games: Students play on their phones

Blast Go

Zombie Escape

Avalanche

Maze Blast

Cave Climb

Blast Out

Mystery Auction

Tour Guide

Food Truck Rush

Tug of War

Alien Blast

Glacier Rush

Board Games: Teacher-led, projected to the class

Like what you see?

More like this

Bug Blast

BlastRace

BlastQuiz

BlastBoard

Seek & Destroy

Mystery Blast

Checkers

Texas Hold 'Em

Da Bomb

Castle Siege

Hot Potato

Market Mayhem

King of the Hill

Bank Heist

Top Corner