A Professor Believes That Students Who Smoke Cigarettes Tend to Have

question 31

Multiple Choice

A professor believes that students who smoke cigarettes tend to have lower grades. He collects data from 1326 randomly selected students at his university and discovers that, on average, students who smoke cigarettes do indeed tend to have lower grade point averages than students who do not smoke.
This study was based on

• A) a randomized comparative experiment.
• B) a matched pairs experiment.
• C) a voluntary response sample.
• D) a probability sample.

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Definitions:

Ounce

A unit of weight in the U.S. customary and British imperial systems, equal to 1/16 of a pound.

Milligrams

A metric unit of mass equal to one thousandth of a gram, commonly used to measure small quantities of substances.

Kilograms

A metric unit of mass equal to 1000 grams.

Ounces

A unit of weight in the avoirdupois system, equal to 1/16 of a pound or approximately 28.35 grams.