A researcher is studying the effect of sleep on how well people over the age of 60 perform on a driving test. She samples 20 seniors from a neighborhood association, tracks their sleep and gives them a driving test. What is the independent variable?

		the 20 people sampled
		sleep
		age
		performance on driving test

6C)

n experimental psychologist interested in the relationship between alcohol consumption and memory conducts a survey of 213 students in his cognitive psychology course. He asks them to report their consumption of alcohol (alcoholic drinks consumed per week). He plans on conducting an analysis of these data together with the grade point averages of the same students. What would be the independent variable in this study?

		Number of alcoholic drinks consumed per week
		Cognitive psychology students
		Grade point averages
		Age