Question

In an experimental study, men with erectile disorder received either Viagra or a placebo. In this study, the drug dosage (none versus peak dose) was the
A) confounding variable.

B) dependent variable.

C) random sample.

D) independent variable.

Answer 1

It seems like the study wants to measure the effectiveness of Viagra to a relative level. So it's changing the drug dosage from 0 (a placebo to avoid bias) to peak dose.

What's being changed is drug dosage, so what do you think? Recall independent variable is what you change. A random sample is a statistical term where an SRS is taken out of a population. Dependent variable is what you measure. Confounding variable is an unintentional factor that skews results and creates bias in a study.