Question 1

What does the word 'unit' mean, in statistical terms?

Accepted Answer

A) The unit of measurement that is used (for example feet, inches, etc.) 
B) The people doing the sampling are called the sampling unit. 
C) A single individual or object to be measured. 
D) None of the above.

Question 2

For Questions use the following narrative
Narrative: Valentine spending
Suppose you want to find out how much money each adult will spend on Valentine's Day this year, on average.
-{Valentine spending narrative} Suppose you go to a local mall the day before Valentine's Day and ask the first 50 people you see.What type of sample are you getting here?

Accepted Answer

A) A self-selected sample 
B) A convenience sample 
C) A cluster sample 
D) A systematic sample

Question 3

For Questions use the following narrative
Narrative: Exit poll
Suppose a recent election exit pollster reports that "Forty-eight percent of the voters polled said they voted for Candidate A.The margin of error for this survey is plus or minus 2.5 percentage points." Assume the exit poll was designed and conducted correctly.
-{Exit poll narrative} About how many people were sampled?

Accepted Answer

A) 40 
B) 1,600 
C) 16,000 
D) Not enough information to tell.

Question 4

The __________ is the entire collection of units about which we would like information; the __________ is the collection of units we actually measure.

Accepted Answer

The answer of The __________ is the entire collection of...

Question 5

For Questions use the following narrative
Narrative: Boat show
The annual Vacation & Boat Show in Columbus, Ohio offers four types of attractions: boats, fishing gear, outdoor equipment, and vacation planning services.Tickets sell for $6 per person, and children under 5 get in free.This year the show organizers want to find out which attraction was most popular, so they surveyed 100 people at random who attended the show, and asked them.The results showed that 67% of them liked the boats best.
-{Boat show narrative} Specify the population.

Accepted Answer

The answer of For Questions use the following narrative
Narrative: Boat...

Question 6

What is wrong with using a list of registered voters to predict election outcomes?

Accepted Answer

The answer of What is wrong with using a list...

Question 7

Which of the following is a research strategy that involves the researcher manipulating the participants' environment in some way?

Accepted Answer

A) Sample survey 
B) Randomized experiment 
C) Observational study 
D) None of the above

Question 8

For Questions use the following narrative
Narrative: Exit poll
Suppose a recent election exit pollster reports that "Forty-eight percent of the voters polled said they voted for Candidate A.The margin of error for this survey is plus or minus 2.5 percentage points." Assume the exit poll was designed and conducted correctly.
-{Exit poll narrative} What can be concluded about Candidate A?

Accepted Answer

A) 48% of all voters will vote for Candidate A. 
B) We are confident that between 45.5% and 50.5% of all voters will vote for Candidate A.This means he/she will win the election, because 50.5% is more than half of the votes. 
C) We are confident that between 45.5% and 50.5% of the voters will vote for Candidate A.The election is 'too close to call' at this point.It could go either way. 
D) None of the above

Question 9

It is difficult to survey certain groups of people, such as the homeless population, because they don't have addresses, phone numbers, or residences.Explain how you would select a sample from the homeless population in your city, and comment on how 'random' you feel it would be.

Accepted Answer

The answer of It is difficult to survey certain groups...

Question 10

Many large surveys use a combination of sampling methods, applying them one at a time.This is called a (an) __________ sampling plan.

Accepted Answer

The answer of Many large surveys use a combination of...

Question 11

For Questions use the following narrative
Narrative: Boat show
The annual Vacation & Boat Show in Columbus, Ohio offers four types of attractions: boats, fishing gear, outdoor equipment, and vacation planning services.Tickets sell for $6 per person, and children under 5 get in free.This year the show organizers want to find out which attraction was most popular, so they surveyed 100 people at random who attended the show, and asked them.The results showed that 67% of them liked the boats best.
-{Boat show narrative} The 100 people who were surveyed make up which group?

Accepted Answer

A) The population 
B) The sample 
C) The sampling frame 
D) None of the above

Question 12

A (an) __________ is a survey in which the entire population is measured.

Accepted Answer

The answer of A (an) __________ is a survey in...

Question 13

Assume you have a sampling frame of your entire population of interest, which is comprised of 100 people's names.Which of the following sources could not be used to select a truly simple random sample of 10 people from this population?

Accepted Answer

A) Assign each person a number from 001 to 100 and choose 10 numbers using a random number table. 
B) Put each of the 100 names on equal sized pieces of paper, put the names in a hat, mix thoroughly, and draw out 10 names. 
C) Put the names in alphabetical order and take the first 10 names on the list. 
D) Each of the above methods would yield a truly simple random sample.

Question 14

For Questions use the following narrative
Narrative: Apartment complex
Suppose you want to survey the opinions of the residents of an apartment complex.The complex contains 100 buildings, each with 8 units per building, for a total of 800 units.You decide to sample 160 of the units.
-{Apartment complex narrative} Suppose 50 of the buildings (400 total units) are for singles, and 50 buildings (400 units) are for non-singles.You randomly select 80 single units and then you randomly select 80 non-single units.What sampling method did you use?

Accepted Answer

A) A systematic sample. 
B) A stratified sample. 
C) A cluster sample. 
D) A simple random sample

Question 15

Give a situation where a simple random sample would be impossible or not feasible, and a systematic sample would be necessary.

Accepted Answer

The answer of Give a situation where a simple random...

Question 16

Why do researchers conduct experiments that are randomized (that is, participants are randomly assigned to the groups being compared)?

Accepted Answer

The answer of Why do researchers conduct experiments that are...

Question 17

What is one advantage of a cluster sample over a simple random sample?

Accepted Answer

The answer of What is one advantage of a cluster...

Question 18

Why should you be suspicious of a survey that was conducted on a random sample of 2,000 people but was done in one night (this is typical of the 'instant polling' that goes on in the media).

Accepted Answer

The answer of Why should you be suspicious of a...

Question 19

You have 15 employees working for you: Bob, Sue, Jim, Alex, DJ, Ann, Leslie, Eric, Deb, Tom, Clint, Richard, Tami, Ellen, and Katie.Use the following set of random numbers (generated from the computer program called Minitab) to take a simple random sample of 3 employees to serve on the donut committee: 1453131401146111619116112912015.Which employees got chosen for the donut committee? (Keep the employees in the order given when you assign numbers to them and do not start numbering with 0, start with 1.)

Accepted Answer

A) Ellen, Tami, Bob 
B) Ellen, Tami, Ellen 
C) Bob, Alex, DJ 
D) None of the above

Question 20

Which of the following types of samples should be avoided at all costs?

Accepted Answer

A) A haphazard sample 
B) A self-selected sample 
C) A volunteer sample 
D) All of the above

Exam 4: How to Get a Good Sample