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:

COUNTIF(range,criteria)

A function in spreadsheet software that counts the number of cells within a range that meet a specified condition.

Specified Criteria

Pre-determined standards or conditions that must be met or complied with.

Departmental Contribution

The amount of revenue contributed by a specific department after deducting its direct and indirect costs.