In an Experiment to Study the Effects of Caffeine on Performance

question 75

Multiple Choice

In an experiment to study the effects of caffeine on performance, an experimenter asked the male students in an introductory psychology class to drink two regular Pepsis before a test and the female students to drink two caffeine-free Pepsis. She then compared performance of the two groups on the test. A confounding variable in this study is:

• A) whether participants had studied for the test.
• B) the type of drink.
• C) the gender of the participants.
• D) the amount of caffeine in the Pepsi.

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Definitions:

Long Run

A period in which all factors of production and costs are variable, allowing firms to adjust all inputs in response to market conditions.

Short Run

A period in economics during which at least one input or resource is fixed, limiting the ability of the firm to adjust all inputs freely.

Market Demand

Represents the total quantity of a good or service that all consumers in a market are willing and able to purchase at various prices over a specific period of time.

Price Elasticity

A measure of how much the quantity demanded of a good responds to a change in the price of that good, expressed as a percentage.