During swallowing, the air passageway of the phaynx is covered by the epiglottis
Answer:
An independent variable is one which can be changed or manipulated in an experiment. The effect of the independent variable is observed on the dependent variable. The dependent variable is the one which does not change or manipulated in an experiment by the investigator. The changes that occur in the dependent variable with respect to the independent variable is the outcome of the experimentation process.
In the given situation, the medicine and the placebo drug are the independent samples whereas the effect of the medicine and placebo drug can be observed on the time they require to cure the headache is the dependent variable.
