A Researcher Computes the Mean Difference in Locomotion in a Sample

question 33

Multiple Choice

A researcher computes the mean difference in locomotion in a sample of 12 rats before and 30 min after an injection of amphetamine.Rats were placed in a box with infrared beams.The number of times rats crossed the beams was used as a measure of locomotion.The mean difference in locomotion was 6.2 ± 8.4 (M_D ± S_D) and this difference was significant.What is the effect size for this result using estimated Cohen's d?

• A) d = 0.74 (medium effect)
• B) d = 1.36 (medium effect)
• C) d = 0.74 (large effect)
• D) d = 1.36 (large effect)

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Definitions:

Expected Utility Function

A mathematical expression that represents a consumer's preference for uncertain outcomes, weighting each outcome by its probability of occurrence.

Von Neuman-Morgenstern Utility Function

A utility function that accounts for the existence of risk and uncertainty, allowing for the calculation of expected utility.

Wealth

The total value of all assets owned by an individual, community, company, or country, minus any liabilities.

Probability

A measure of the likelihood that a specified event will occur, expressed as a number between 0 and 1.