AP Statistics : Data Collection
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Example Questions
Example Question #2 : How To Establish Blind Experiments
Which of the following is an example of a single-blind experiment?
An experiment in which the researchers and test subjects are unaware of who is receiving a placebo and who is receiving a therapy.
An experiment in which the researchers are aware of who is receiving a placebo and who is receiving a therapy, but the test subjects are unaware.
Two of the answers are correct
An experiment in which the test subjects are aware of who is receiving a placebo and who is receiving a therapy, but the researchers are unaware.
An experiment in which the researchers and test subjects are aware of who is receiving a placebo and who is receiving a therapy.
Two of the answers are correct
In a single-blind experiment, one group (either the researchers or the test subjects) must be blinded while the other group is aware of who is receiving a placebo and who is receiving a therapy.
The following two examples are correct:
-An experiment in which the test subjects are aware of who is receiving a placebo and who is receiving a therapy, but the researchers are unaware.
-An experiment in which the researchers are aware of who is receiving a placebo and who is receiving a therapy, but the test subjects are unaware.
Example Question #1 : How To Establish Blind Experiments
Alpha Corporation developed a new pill to treat elevated glucose levels. They want to test the efficiency of the pill to lower glucose levels by gathering a sample of people with high glucose and giving them either:
1) A daily dose of their new pill ("Experimental Group")
2) A daily placebo pill that looks the same but does not do anything ("Placebo Group")
How can they make this a "Blind Study"?
Keep the participant identities hidden from the experimenters permanently.
Give the pill to people with high blood glucose and low blood glucose.
Give all participants both pills.
Blindfold the participants while they take the pills.
Randomly sort people into the Experimental or Placebo groups, without letting them know which pill they received.
Randomly sort people into the Experimental or Placebo groups, without letting them know which pill they received.
A blind experiment is one in which the participant does not know which experimental group they are in-- which is accomplished by not letting them know if they are in the Experimental or Placebo group.
Example Question #301 : Ap Statistics
A drug company wants to test a new pill that should make people's nails grow twice as quickly as normal. How can they make the study a blind study?
Give all participants the actual pill and measure nail growth.
Give one group of people the actual pill and one group a placebo, but don't tell the participants which pill they are receiving.
Give all participants the placebo pill and measure nail growth.
This test cannot be done as a blind study.
Give half participants the placebo pill and tell them they had the actual pill, and give the rest the actual pill but tell them they have the placebo pill.
Give one group of people the actual pill and one group a placebo, but don't tell the participants which pill they are receiving.
In order for a study to be "blind," the participants can't know which group they are sorted into. For a study to be double-blind, which is even better, the researchers should also be blind to which group participants are in until the study is completed.
Example Question #1 : How To Conduct Matched Pairs Experiments
An company wants to test how much a fuel additive improves the fuel efficiency of cars and has 
Matched pairs 
Two-sample 
One-sample proportion 
Two-sample 
Chi-square test of association
Matched pairs
A matched pairs design t test is the best choice because it will compare the effectiveness of the fuel additive by looking at the means differences of two sample sets where the only variable that is changed from one test to the other test is the introduction of the fuel additive. It makes no sense to compare the performance of, for example, a Ford Mustang with the additive against a Toyota Prius hybrid without the additive. It becomes crucial to compare fuel efficiency with and without the fuel additive for each car.
Example Question #1 : How To Conduct Matched Pairs Experiments
For which of these experiments would a matched pairs design not be ideal?
Evaluating the effectiveness of a diet.
Comparing effectiveness of two coaches and their methods.
Evaluating effectiveness of a test preparation regimen.
Comparing strength of right arms against strength of left arms.
Evaluating effectiveness of a new type of oil filter in various cars.
Comparing effectiveness of two coaches and their methods.
Remember that a matched pairs design tends to involve "before and after" or "with and without" or "left and right" using the same experimental units.
Therefore comparing effectiveness of two coaches and their methods would not be an experiment for the matched pairs design.
Example Question #1 : How To Conduct A Sample Survey
A company asks you to conduct a survey to discover what consumers generally want. What should the survey population be?
All possible consumers
All of the company's customers
Future consumers
Past consumers
All possible consumers
The company wants a survey on what consumers want. That means they are interested in all possible consumers. The other groups are too specific.
Example Question #1 : How To Conduct A Sample Survey
Your AP Statistics teacher asks you to conduct a survey to determine the most popular cereal brand at your high school. Which of the following should be the survey population in your study?
All high school students in your city
All students in your high school
All high school students in the United States
Students in your grade level
Students in your AP Statistics Class
All students in your high school
Since your teacher has asked that you determine the most popular cereal brand at your high school, the survey population should be limited to only your high school. Other students' preferences of cereal brands around the nation will have no impact on the survey results.
Additionally, surveying only students in your AP Statistics class or only students in a particular grade level would not be representative of all students in your high school. Therefore, the correct survey population is all students in your high school.
Example Question #1 : How To Conduct A Sample Survey
Shawn would like to determine what the most popular television channel is in his town, called Hearne.
Which of the following would be an appropriate target population for the survey?
Residents of the town whose contact information can be found in the local directory
Students at the local high school
Purchasers of a television at the local electronics store
Attendees of a mass at a local Church
Shoppers at the local grocery store
Residents of the town whose contact information can be found in the local directory
Since Shawn would like to know the most popular television channel in his town, he must include all residents of the town in his target population. The sample must come from the directory and each person in the directory should have an equal chance of being selected. The incorrect options are too narrowly focused and are not representative of the town.
Example Question #1 : How To Conduct A Sample Survey
Which of the following is a continuous variable?
i. The average weight of a newborn puppy
ii. The number of snow days during the last month
iii. The amount of time that it takes to read a book
i and iii
None of the above
ii and iii
i only
i and ii
i and iii
A continuous variable can take on an infinite continuum of possible real number values. Weight and the amount of time to read a book are continuous because it is impossible to write down all the distinct potential values.
Example Question #112 : Data
For which of these is a binomial probability model most reasonable?
The number of times, out of 
The number of people surveyed until someone who has no pets is found.
The number of cards drawn from a deck until the two jokers are drawn.
The colors of the gummy bears in a particular bag of gummy bears from a randomly selected store rack.
The number of times a randomly selected college student has gone to the beach in the last year.
The number of times, out of
A binomial model counts the number of successes out of a specific number of attempts at a task when each attempt has a constant probability of success. The correct choice is the one that specifies the number of attempts.
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