A Random Person Is Selected from a Large Population in Which

question 74

Multiple Choice

A random person is selected from a large population in which 5% are users of a dangerous illegal drug.A drug test that correctly identifies users 99% of the times and nonusers 95% of the time is administered to this individual and gives a positive result.What is the probability that this individual is actually a user of this drug?

• A)0.99
• B)0.94
• C)0.61
• D)0.53
• E)0.51

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Definitions:

Marginal Benefit

The additional satisfaction or utility that a person receives from consuming an additional unit of a good or service.

Additional Serving

An extra portion or second helping of food provided after the consumption of an initial serving.

Economic Thinking

A method of evaluating issues and making decisions based on the principles of economics, such as cost-benefit analysis, scarcity, and opportunity cost.

Marginal Change

A small, incremental adjustment to an existing set of conditions or a decision.