Researchers Wish to Test the Effectiveness of a Drug Designed

question 21

Multiple Choice

Researchers wish to test the effectiveness of a drug designed to treat depression.Seven clinically depressed patients are given a standardized depression test before taking the drug and are evaluated 4 weeks later using the same test.It is known that the scores from this particular test are not normally distributed.The scores are shown here. ​ ​
Use a sign test to conclude whether the drug can be associated with a median decrease in depression level.Choose the correct p-value and conclusion.(Use α = 0.05.)

• A) p = 0.5000; there appears to be no median decrease in depression.
• B) p = 0.8125; there appears to be no median decrease in depression.
• C) p = 0.1875; there appears to be no median decrease in depression.
• D) p = 0.1875; there appears to be a median decrease in depression.

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Definitions:

Negative Reinforcer

Any unpleasant stimulus that, when removed after a response, strengthens the response, making it more likely to occur in the future.

Immediate Reinforcement

The provision of a reward directly following a desired behavior to strengthen its occurrence.

Fixed-interval Schedule

A reinforcement schedule where a reward is given for the first response after a predetermined time period has passed.

Conditioned Reinforcers

Stimuli that acquire their reinforcing power through association with primary reinforcers, playing a role in shaping behavior.