Question

Scientists are testing the effectiveness of 3 different viral medicines (or vaccines) in protecting against the common cold. They sign up 1,200 human volunteers and split them into three groups. So each group of 400 people is given one of the vaccines. The groups are studied for five years, and the scientists record how many colds they get each year. What is the dependent variable in this investigation?

A. Different viral medications
B. The number of years
C. The type of common cold virus
D. The number of colds each year

Answer 1

D. The number of colds each year. The dependent variable in this investigation is the number of colds each year.

Step-by-step explanation:

The dependent variable in this investigation is the number of colds each year. The scientists are studying the effectiveness of different viral medicines in protecting against the common cold. Therefore, they are interested in recording the number of colds that the volunteers in each group get each year. This variable will help determine the effectiveness of the vaccines in preventing colds.