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Twenty volunteers were assigned at random to one of two groups (10 people in each group). One group would take Vitamin C for two weeks, while the second group would take a placebo. At the end of the study, the proportion of colds in the two groups will be compared.
-What is the explanatory variable in the study?
A) Getting a cold (or not)
B) Taking Vitamin C (or a Placebo)
C) Getting 8 hours of sleep a night (or not)
D) Exposure to other people with colds (or not)

Question

Quizplus · Accepted Answer

The explanatory variable is the one that is manipulated by the researchers to observe its effect on the outcome. In this study, the manipulation involves whether participants take Vitamin C or a placebo, making it the explanatory variable.

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