Question

A group of medical researchers investigated the effects of a drug called Pressure Drop X on lowering blood pressure in a group of women between the ages of 60 and 80 years old. The researchers did the following experiment and obtained the indicated results: One group of 100 women took a tablet containing Pressure Drop Z for 4 weeks – 95 of these women experienced decreased blood pressure by at least 10%. Another group of 100 women were given a tablet with no added Pressure Drop Z for 4 weeks – 10 of these women experienced decreased their blood pressure by 10%. What is the independent variable in this experiment?

	Amount of Pressure Drop Z
	Blood pressure
	The age and gender of the participants
	The 4 week time period and sample size of 100
	The group of women that received the pills with no added Pressure Drop Z

Answer 1

If we see carefully, then the outcome or response depends on whether or not the women received Pressure Drop Z.

Therefore, "decrease in blood pressure" is the dependent variable and the "amount of Pressure Drop Z" is the independent variable.