A Researcher Computes the Mean Difference in Locomotion in a Sample

question 47

Multiple Choice

A researcher computes the mean difference in locomotion in a sample of 12 rats before and 30 minutes 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 ( ) ,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:

Solution

A homogeneous mixture composed of two or more substances, where one substance (the solute) is dissolved in another (the solvent).

Electrolytes

Minerals in the body that have an electric charge, crucial for hydrating the body, regulating nerve and muscle function, balancing blood acidity and pressure.

Ions

Atoms or molecules with a net electric charge due to the loss or gain of one or more electrons.

Solution

A homogeneous mixture composed of two or more substances, where the solute is dissolved in the solvent.